diff --git a/common/lib/capa/capa/inputtypes.py b/common/lib/capa/capa/inputtypes.py
index b4e9fe1654..18bc92f0a3 100644
--- a/common/lib/capa/capa/inputtypes.py
+++ b/common/lib/capa/capa/inputtypes.py
@@ -655,9 +655,9 @@ class MatlabInput(CodeInput):
         # Check if problem has been queued
         self.queuename = 'matlab'
         self.queue_msg = ''
-        if 'queue_msg' in self.input_state and self.status in ['queued','incomplete', 'unsubmitted']:
+        if 'queue_msg' in self.input_state and self.status in ['queued', 'incomplete', 'unsubmitted']:
             self.queue_msg = self.input_state['queue_msg']
-        if 'queued' in self.input_state and self.input_state['queuestate'] is not None:
+        if 'queuestate' in self.input_state and self.input_state['queuestate'] == 'queued':
             self.status = 'queued'
             self.queue_len = 1
             self.msg = self.plot_submitted_msg
@@ -702,7 +702,7 @@ class MatlabInput(CodeInput):
     def _extra_context(self):
         ''' Set up additional context variables'''
         extra_context = {
-                'queue_len': self.queue_len,
+                'queue_len': str(self.queue_len),
                 'queue_msg': self.queue_msg
                 }
         return extra_context
diff --git a/common/lib/capa/capa/tests/test_inputtypes.py b/common/lib/capa/capa/tests/test_inputtypes.py
index 250cedd549..e7f0b784bc 100644
--- a/common/lib/capa/capa/tests/test_inputtypes.py
+++ b/common/lib/capa/capa/tests/test_inputtypes.py
@@ -361,7 +361,6 @@ class MatlabTest(unittest.TestCase):
                  'feedback': {'message': '3'}, }
         elt = etree.fromstring(self.xml)
 
-        input_class = lookup_tag('matlabinput')
         the_input = self.input_class(test_system, elt, state)
         context = the_input._get_render_context()
 
@@ -381,6 +380,31 @@ class MatlabTest(unittest.TestCase):
 
         self.assertEqual(context, expected)
 
+    def test_rendering_while_queued(self):
+        state = {'value': 'print "good evening"',
+                 'status': 'incomplete',
+                 'input_state': {'queuestate': 'queued'},
+                 }
+        elt = etree.fromstring(self.xml)
+
+        the_input = self.input_class(test_system, elt, state)
+        context = the_input._get_render_context()
+        expected = {'id': 'prob_1_2',
+                    'value': 'print "good evening"',
+                   'status': 'queued',
+                   'msg': self.input_class.plot_submitted_msg,
+                   'mode': self.mode,
+                   'rows': self.rows,
+                   'cols': self.cols,
+                   'queue_msg': '',
+                   'linenumbers': 'true',
+                   'hidden': '',
+                   'tabsize': int(self.tabsize),
+                   'queue_len': '1',
+                   }
+
+        self.assertEqual(context, expected)
+
     def test_plot_data(self):
         get = {'submission': 'x = 1234;'}
         response = self.the_input.handle_ajax("plot", get)
@@ -391,6 +415,43 @@ class MatlabTest(unittest.TestCase):
         self.assertTrue(self.the_input.input_state['queuekey'] is not None)
         self.assertEqual(self.the_input.input_state['queuestate'], 'queued')
 
+    def test_ungraded_response_success(self):
+        queuekey = 'abcd'
+        input_state = {'queuekey': queuekey, 'queuestate': 'queued'}
+        state = {'value': 'print "good evening"',
+                 'status': 'incomplete',
+                 'input_state': input_state,
+                 'feedback': {'message': '3'}, }
+        elt = etree.fromstring(self.xml)
+
+        the_input = self.input_class(test_system, elt, state)
+        inner_msg = 'hello!'
+        queue_msg = json.dumps({'msg': inner_msg})
+
+        the_input.ungraded_response(queue_msg, queuekey)
+        self.assertTrue(input_state['queuekey'] is None)
+        self.assertTrue(input_state['queuestate'] is None)
+        self.assertEqual(input_state['queue_msg'], inner_msg)
+
+    def test_ungraded_response_key_mismatch(self):
+        queuekey = 'abcd'
+        input_state = {'queuekey': queuekey, 'queuestate': 'queued'}
+        state = {'value': 'print "good evening"',
+                 'status': 'incomplete',
+                 'input_state': input_state,
+                 'feedback': {'message': '3'}, }
+        elt = etree.fromstring(self.xml)
+
+        the_input = self.input_class(test_system, elt, state)
+        inner_msg = 'hello!'
+        queue_msg = json.dumps({'msg': inner_msg})
+
+        the_input.ungraded_response(queue_msg, 'abc')
+        self.assertEqual(input_state['queuekey'], queuekey)
+        self.assertEqual(input_state['queuestate'], 'queued')
+        self.assertFalse('queue_msg' in input_state)
+
+
 
 
 
diff --git a/common/lib/xmodule/xmodule/capa_module.py b/common/lib/xmodule/xmodule/capa_module.py
index ca7e052e7e..2097e4d4ee 100644
--- a/common/lib/xmodule/xmodule/capa_module.py
+++ b/common/lib/xmodule/xmodule/capa_module.py
@@ -108,11 +108,10 @@ class CapaModule(CapaFields, XModule):
     '''
     icon_class = 'problem'
 
-
     js = {'coffee': [resource_string(__name__, 'js/src/capa/display.coffee'),
                      resource_string(__name__, 'js/src/collapsible.coffee'),
                      resource_string(__name__, 'js/src/javascript_loader.coffee'),
-                    ],
+                     ],
           'js': [resource_string(__name__, 'js/src/capa/imageinput.js'),
                  resource_string(__name__, 'js/src/capa/schematic.js')
                  ]}
@@ -367,11 +366,11 @@ class CapaModule(CapaFields, XModule):
             self.set_state_from_lcp()
 
             # Prepend a scary warning to the student
-            warning  = '<div class="capa_reset">'\
-                       '<h2>Warning: The problem has been reset to its initial state!</h2>'\
-                       'The problem\'s state was corrupted by an invalid submission. ' \
-                       'The submission consisted of:'\
-                       '<ul>'
+            warning = '<div class="capa_reset">'\
+                      '<h2>Warning: The problem has been reset to its initial state!</h2>'\
+                      'The problem\'s state was corrupted by an invalid submission. ' \
+                      'The submission consisted of:'\
+                      '<ul>'
             for student_answer in student_answers.values():
                 if student_answer != '':
                     warning += '<li>' + cgi.escape(student_answer) + '</li>'
@@ -388,7 +387,6 @@ class CapaModule(CapaFields, XModule):
 
         return html
 
-
     def get_problem_html(self, encapsulate=True):
         '''Return html for the problem.  Adds check, reset, save buttons
         as necessary based on the problem config and state.'''
@@ -401,7 +399,6 @@ class CapaModule(CapaFields, XModule):
         except Exception, err:
             html = self.handle_problem_html_error(err)
 
-
         # The convention is to pass the name of the check button
         # if we want to show a check button, and False otherwise
         # This works because non-empty strings evaluate to True
@@ -454,7 +451,7 @@ class CapaModule(CapaFields, XModule):
             'score_update': self.update_score,
             'input_ajax': self.handle_input_ajax,
             'ungraded_response': self.handle_ungraded_response
-            }
+        }
 
         if dispatch not in handlers:
             return 'Error'
@@ -472,7 +469,7 @@ class CapaModule(CapaFields, XModule):
         d.update({
             'progress_changed': after != before,
             'progress_status': Progress.to_js_status_str(after),
-            })
+        })
         return json.dumps(d, cls=ComplexEncoder)
 
     def is_past_due(self):
@@ -535,7 +532,6 @@ class CapaModule(CapaFields, XModule):
 
         return False
 
-
     def update_score(self, get):
         """
         Delivers grading response (e.g. from asynchronous code checking) to
@@ -590,7 +586,6 @@ class CapaModule(CapaFields, XModule):
         self.set_state_from_lcp()
         return response
 
-
     def get_answer(self, get):
         '''
         For the "show answer" button.
@@ -700,7 +695,6 @@ class CapaModule(CapaFields, XModule):
             'max_value': score['total'],
         })
 
-
     def check_problem(self, get):
         ''' Checks whether answers to a problem are correct, and
             returns a map of correct/incorrect answers:
@@ -783,7 +777,7 @@ class CapaModule(CapaFields, XModule):
         self.system.track_function('save_problem_check', event_info)
 
         if hasattr(self.system, 'psychometrics_handler'):  # update PsychometricsData using callback
-            self.system.psychometrics_handler(self.get_instance_state())
+            self.system.psychometrics_handler(self.get_state_for_lcp())
 
         # render problem into HTML
         html = self.get_problem_html(encapsulate=False)
diff --git a/common/lib/xmodule/xmodule/tests/test_capa_module.py b/common/lib/xmodule/xmodule/tests/test_capa_module.py
index 1fefbb64cd..d94345fe1c 100644
--- a/common/lib/xmodule/xmodule/tests/test_capa_module.py
+++ b/common/lib/xmodule/xmodule/tests/test_capa_module.py
@@ -35,6 +35,7 @@ class CapaFactory(object):
 """
 
     num = 0
+
     @staticmethod
     def next_num():
         CapaFactory.num += 1
@@ -49,7 +50,7 @@ class CapaFactory(object):
     def answer_key():
         """ Return the key stored in the capa problem answer dict """
         return ("-".join(['i4x', 'edX', 'capa_test', 'problem',
-                        'SampleProblem%d' % CapaFactory.num]) +
+                         'SampleProblem%d' % CapaFactory.num]) +
                 "_2_1")
 
     @staticmethod
@@ -120,7 +121,6 @@ class CapaFactory(object):
         return module
 
 
-
 class CapaModuleTest(unittest.TestCase):
 
     def setUp(self):
@@ -142,9 +142,6 @@ class CapaModuleTest(unittest.TestCase):
         self.assertNotEqual(module.url_name, other_module.url_name,
                             "Factory should be creating unique names for each problem")
 
-
-
-
     def test_correct(self):
         """
         Check that the factory creates correct and incorrect problems properly.
@@ -155,7 +152,6 @@ class CapaModuleTest(unittest.TestCase):
         other_module = CapaFactory.create(correct=True)
         self.assertEqual(other_module.get_score()['score'], 1)
 
-
     def test_showanswer_default(self):
         """
         Make sure the show answer logic does the right thing.
@@ -165,14 +161,12 @@ class CapaModuleTest(unittest.TestCase):
         problem = CapaFactory.create()
         self.assertFalse(problem.answer_available())
 
-
     def test_showanswer_attempted(self):
         problem = CapaFactory.create(showanswer='attempted')
         self.assertFalse(problem.answer_available())
         problem.attempts = 1
         self.assertTrue(problem.answer_available())
 
-
     def test_showanswer_closed(self):
 
         # can see after attempts used up, even with due date in the future
@@ -182,21 +176,19 @@ class CapaModuleTest(unittest.TestCase):
                                                due=self.tomorrow_str)
         self.assertTrue(used_all_attempts.answer_available())
 
-
         # can see after due date
         after_due_date = CapaFactory.create(showanswer='closed',
-                                               max_attempts="1",
-                                               attempts="0",
-                                               due=self.yesterday_str)
+                                            max_attempts="1",
+                                            attempts="0",
+                                            due=self.yesterday_str)
 
         self.assertTrue(after_due_date.answer_available())
 
-
         # can't see because attempts left
         attempts_left_open = CapaFactory.create(showanswer='closed',
-                                               max_attempts="1",
-                                               attempts="0",
-                                               due=self.tomorrow_str)
+                                                max_attempts="1",
+                                                attempts="0",
+                                                due=self.tomorrow_str)
         self.assertFalse(attempts_left_open.answer_available())
 
         # Can't see because grace period hasn't expired
@@ -207,8 +199,6 @@ class CapaModuleTest(unittest.TestCase):
                                             graceperiod=self.two_day_delta_str)
         self.assertFalse(still_in_grace.answer_available())
 
-
-
     def test_showanswer_past_due(self):
         """
         With showanswer="past_due" should only show answer after the problem is closed
@@ -222,20 +212,18 @@ class CapaModuleTest(unittest.TestCase):
                                                due=self.tomorrow_str)
         self.assertFalse(used_all_attempts.answer_available())
 
-
         # can see after due date
         past_due_date = CapaFactory.create(showanswer='past_due',
-                                               max_attempts="1",
-                                               attempts="0",
-                                               due=self.yesterday_str)
+                                           max_attempts="1",
+                                           attempts="0",
+                                           due=self.yesterday_str)
         self.assertTrue(past_due_date.answer_available())
 
-
         # can't see because attempts left
         attempts_left_open = CapaFactory.create(showanswer='past_due',
-                                               max_attempts="1",
-                                               attempts="0",
-                                               due=self.tomorrow_str)
+                                                max_attempts="1",
+                                                attempts="0",
+                                                due=self.tomorrow_str)
         self.assertFalse(attempts_left_open.answer_available())
 
         # Can't see because grace period hasn't expired, even though have no more
@@ -260,31 +248,28 @@ class CapaModuleTest(unittest.TestCase):
                                                due=self.tomorrow_str)
         self.assertTrue(used_all_attempts.answer_available())
 
-
         # can see after due date
         past_due_date = CapaFactory.create(showanswer='finished',
-                                               max_attempts="1",
-                                               attempts="0",
-                                               due=self.yesterday_str)
+                                           max_attempts="1",
+                                           attempts="0",
+                                           due=self.yesterday_str)
         self.assertTrue(past_due_date.answer_available())
 
-
         # can't see because attempts left and wrong
         attempts_left_open = CapaFactory.create(showanswer='finished',
-                                               max_attempts="1",
-                                               attempts="0",
-                                               due=self.tomorrow_str)
+                                                max_attempts="1",
+                                                attempts="0",
+                                                due=self.tomorrow_str)
         self.assertFalse(attempts_left_open.answer_available())
 
         # _can_ see because attempts left and right
         correct_ans = CapaFactory.create(showanswer='finished',
-                                               max_attempts="1",
-                                               attempts="0",
-                                               due=self.tomorrow_str,
-                                               correct=True)
+                                         max_attempts="1",
+                                         attempts="0",
+                                         due=self.tomorrow_str,
+                                         correct=True)
         self.assertTrue(correct_ans.answer_available())
 
-
         # Can see even though grace period hasn't expired, because have no more
         # attempts.
         still_in_grace = CapaFactory.create(showanswer='finished',
@@ -294,7 +279,6 @@ class CapaModuleTest(unittest.TestCase):
                                             graceperiod=self.two_day_delta_str)
         self.assertTrue(still_in_grace.answer_available())
 
-
     def test_closed(self):
 
         # Attempts < Max attempts --> NOT closed
@@ -322,7 +306,6 @@ class CapaModuleTest(unittest.TestCase):
                                     due=self.yesterday_str)
         self.assertTrue(module.closed())
 
-
     def test_parse_get_params(self):
 
         # We have to set up Django settings in order to use QueryDict
@@ -348,7 +331,6 @@ class CapaModuleTest(unittest.TestCase):
                             "Output dict should have key %s" % original_key)
             self.assertEqual(valid_get_dict[original_key], result[key])
 
-
         # Valid GET param dict with list keys
         valid_get_dict = self._querydict_from_dict({'input_2[]': ['test1', 'test2']})
         result = CapaModule.make_dict_of_responses(valid_get_dict)
@@ -366,12 +348,11 @@ class CapaModuleTest(unittest.TestCase):
         with self.assertRaises(ValueError):
             result = CapaModule.make_dict_of_responses(invalid_get_dict)
 
-
         # Two equivalent names (one list, one non-list)
         # One of the values would overwrite the other, so detect this
         # and raise an exception
         invalid_get_dict = self._querydict_from_dict({'input_1[]': 'test 1',
-                                                    'input_1': 'test 2'})
+                                                      'input_1': 'test 2'})
         with self.assertRaises(ValueError):
             result = CapaModule.make_dict_of_responses(invalid_get_dict)
 
@@ -395,7 +376,6 @@ class CapaModuleTest(unittest.TestCase):
 
         return copyDict
 
-
     def test_check_problem_correct(self):
 
         module = CapaFactory.create(attempts=1)
@@ -403,6 +383,7 @@ class CapaModuleTest(unittest.TestCase):
         # Simulate that all answers are marked correct, no matter
         # what the input is, by patching CorrectMap.is_correct()
         # Also simulate rendering the HTML
+        # TODO: pep8 thinks the following line has invalid syntax
         with patch('capa.correctmap.CorrectMap.is_correct') as mock_is_correct,\
                 patch('xmodule.capa_module.CapaModule.get_problem_html') as mock_html:
             mock_is_correct.return_value = True
@@ -439,7 +420,6 @@ class CapaModuleTest(unittest.TestCase):
         # Expect that the number of attempts is incremented by 1
         self.assertEqual(module.attempts, 1)
 
-
     def test_check_problem_closed(self):
         module = CapaFactory.create(attempts=3)
 
@@ -503,12 +483,11 @@ class CapaModuleTest(unittest.TestCase):
         # Expect that the number of attempts is NOT incremented
         self.assertEqual(module.attempts, 1)
 
-
     def test_check_problem_error(self):
 
         # Try each exception that capa_module should handle
-        for exception_class in [StudentInputError, 
-                                LoncapaProblemError, 
+        for exception_class in [StudentInputError,
+                                LoncapaProblemError,
                                 ResponseError]:
 
             # Create the module
@@ -532,9 +511,9 @@ class CapaModuleTest(unittest.TestCase):
             self.assertEqual(module.attempts, 1)
 
     def test_check_problem_error_with_staff_user(self):
-        
+
         # Try each exception that capa module should handle
-        for exception_class in [StudentInputError, 
+        for exception_class in [StudentInputError,
                                 LoncapaProblemError,
                                 ResponseError]:
 
@@ -560,7 +539,6 @@ class CapaModuleTest(unittest.TestCase):
             # Expect that the number of attempts is NOT incremented
             self.assertEqual(module.attempts, 1)
 
-
     def test_reset_problem(self):
         module = CapaFactory.create(done=True)
         module.new_lcp = Mock(wraps=module.new_lcp)
@@ -583,7 +561,6 @@ class CapaModuleTest(unittest.TestCase):
         # Expect that the problem was reset
         module.new_lcp.assert_called_once_with({'seed': None})
 
-
     def test_reset_problem_closed(self):
         module = CapaFactory.create()
 
@@ -598,7 +575,6 @@ class CapaModuleTest(unittest.TestCase):
         # Expect that the problem was NOT reset
         self.assertTrue('success' in result and not result['success'])
 
-
     def test_reset_problem_not_done(self):
         # Simulate that the problem is NOT done
         module = CapaFactory.create(done=False)
@@ -610,7 +586,6 @@ class CapaModuleTest(unittest.TestCase):
         # Expect that the problem was NOT reset
         self.assertTrue('success' in result and not result['success'])
 
-
     def test_save_problem(self):
         module = CapaFactory.create(done=False)
 
@@ -625,7 +600,6 @@ class CapaModuleTest(unittest.TestCase):
         # Expect that the result is success
         self.assertTrue('success' in result and result['success'])
 
-
     def test_save_problem_closed(self):
         module = CapaFactory.create(done=False)
 
@@ -640,7 +614,6 @@ class CapaModuleTest(unittest.TestCase):
         # Expect that the result is failure
         self.assertTrue('success' in result and not result['success'])
 
-
     def test_save_problem_submitted_with_randomize(self):
         module = CapaFactory.create(rerandomize='always', done=True)
 
@@ -651,7 +624,6 @@ class CapaModuleTest(unittest.TestCase):
         # Expect that we cannot save
         self.assertTrue('success' in result and not result['success'])
 
-
     def test_save_problem_submitted_no_randomize(self):
         module = CapaFactory.create(rerandomize='never', done=True)
 
@@ -724,7 +696,6 @@ class CapaModuleTest(unittest.TestCase):
         module = CapaFactory.create(rerandomize="never", done=True)
         self.assertTrue(module.should_show_check_button())
 
-
     def test_should_show_reset_button(self):
 
         attempts = random.randint(1, 10)
@@ -755,7 +726,6 @@ class CapaModuleTest(unittest.TestCase):
         module = CapaFactory.create(max_attempts=0, done=True)
         self.assertTrue(module.should_show_reset_button())
 
-
     def test_should_show_save_button(self):
 
         attempts = random.randint(1, 10)
@@ -823,7 +793,6 @@ class CapaModuleTest(unittest.TestCase):
         html = module.get_problem_html()
         # assert that we got here without exploding
 
-
     def test_get_problem_html(self):
         module = CapaFactory.create()
 
@@ -869,7 +838,6 @@ class CapaModuleTest(unittest.TestCase):
         # Assert that the encapsulated html contains the original html
         self.assertTrue(html in html_encapsulated)
 
-
     def test_get_problem_html_error(self):
         """
         In production, when an error occurs with the problem HTML
@@ -902,7 +870,6 @@ class CapaModuleTest(unittest.TestCase):
         # Expect that the module has created a new dummy problem with the error
         self.assertNotEqual(original_problem, module.lcp)
 
-
     def test_random_seed_no_change(self):
 
         # Run the test for each possible rerandomize value
@@ -920,10 +887,10 @@ class CapaModuleTest(unittest.TestCase):
                 self.assertEqual(seed, 1)
 
             # Check the problem
-            get_request_dict = { CapaFactory.input_key(): '3.14'}
+            get_request_dict = {CapaFactory.input_key(): '3.14'}
             module.check_problem(get_request_dict)
 
-            # Expect that the seed is the same 
+            # Expect that the seed is the same
             self.assertEqual(seed, module.seed)
 
             # Save the problem
@@ -933,7 +900,7 @@ class CapaModuleTest(unittest.TestCase):
             self.assertEqual(seed, module.seed)
 
     def test_random_seed_with_reset(self):
-        
+
         def _reset_and_get_seed(module):
             '''
             Reset the XModule and return the module's seed
@@ -956,7 +923,7 @@ class CapaModuleTest(unittest.TestCase):
             Returns True if *test_func* was successful
             (returned True) within *num_tries* attempts
 
-            *test_func* must be a function 
+            *test_func* must be a function
             of the form test_func() -> bool
             '''
             success = False
@@ -989,9 +956,10 @@ class CapaModuleTest(unittest.TestCase):
                 # Since there's a small chance we might get the
                 # same seed again, give it 5 chances
                 # to generate a different seed
-                success = _retry_and_check(5, 
-                                lambda: _reset_and_get_seed(module) != seed)
-                
+                success = _retry_and_check(5,
+                                           lambda: _reset_and_get_seed(module) != seed)
+
+                # TODO: change this comparison to module.seed is not None?
                 self.assertTrue(module.seed != None)
                 msg = 'Could not get a new seed from reset after 5 tries'
                 self.assertTrue(success, msg)
diff --git a/lms/djangoapps/courseware/management/commands/remove_input_state.py b/lms/djangoapps/courseware/management/commands/remove_input_state.py
index 9adabeafc9..e45d08e351 100644
--- a/lms/djangoapps/courseware/management/commands/remove_input_state.py
+++ b/lms/djangoapps/courseware/management/commands/remove_input_state.py
@@ -76,6 +76,11 @@ class Command(BaseCommand):
             for hist_module in hist_modules:
                 self.remove_studentmodulehistory_input_state(hist_module, save_changes)
 
+            if self.num_visited % 1000 == 0:
+                LOG.info(" Progress: updated {0} of {1} student modules".format(self.num_changed, self.num_visited))
+                LOG.info(" Progress: updated {0} of {1} student history modules".format(self.num_hist_changed,
+                                                                                        self.num_hist_visited))
+
     @transaction.autocommit
     def remove_studentmodule_input_state(self, module, save_changes):
         ''' Fix the grade assigned to a StudentModule'''
diff --git a/lms/djangoapps/psychometrics/psychoanalyze.py b/lms/djangoapps/psychometrics/psychoanalyze.py
index 3e9edcc997..dd60776594 100644
--- a/lms/djangoapps/psychometrics/psychoanalyze.py
+++ b/lms/djangoapps/psychometrics/psychoanalyze.py
@@ -15,7 +15,6 @@ from scipy.optimize import curve_fit
 from django.conf import settings
 from django.db.models import Sum, Max
 from psychometrics.models import *
-from xmodule.modulestore import Location
 
 log = logging.getLogger("mitx.psychometrics")
 
@@ -246,13 +245,16 @@ def generate_plots_for_problem(problem):
         yset['ydat'] = ydat
 
         if len(ydat) > 3:         # try to fit to logistic function if enough data points
-            cfp = curve_fit(func_2pl, xdat, ydat, [1.0, max_attempts / 2.0])
-            yset['fitparam'] = cfp
-            yset['fitpts'] = func_2pl(np.array(xdat), *cfp[0])
-            yset['fiterr'] = [yd - yf for (yd, yf) in zip(ydat, yset['fitpts'])]
-            fitx = np.linspace(xdat[0], xdat[-1], 100)
-            yset['fitx'] = fitx
-            yset['fity'] = func_2pl(np.array(fitx), *cfp[0])
+            try:
+                cfp = curve_fit(func_2pl, xdat, ydat, [1.0, max_attempts / 2.0])
+                yset['fitparam'] = cfp
+                yset['fitpts'] = func_2pl(np.array(xdat), *cfp[0])
+                yset['fiterr'] = [yd - yf for (yd, yf) in zip(ydat, yset['fitpts'])]
+                fitx = np.linspace(xdat[0], xdat[-1], 100)
+                yset['fitx'] = fitx
+                yset['fity'] = func_2pl(np.array(fitx), *cfp[0])
+            except Exception as err:
+                log.debug('Error in psychoanalyze curve fitting: %s' % err)
 
         dataset['grade_%d' % grade] = yset
 
@@ -289,7 +291,7 @@ def generate_plots_for_problem(problem):
                           'info': '',
                           'data': jsdata,
                           'cmd': '[%s], %s' % (','.join(jsplots), axisopts),
-                })
+                          })
 
     #log.debug('plots = %s' % plots)
     return msg, plots
@@ -302,12 +304,12 @@ def make_psychometrics_data_update_handler(course_id, user, module_state_key):
     Construct and return a procedure which may be called to update
     the PsychometricsData instance for the given StudentModule instance.
     """
-    sm = studentmodule.objects.get_or_create(
-        course_id=course_id,
-        student=user,
-        module_state_key=module_state_key,
-        defaults={'state': '{}', 'module_type': 'problem'},
-    )
+    sm, status = StudentModule.objects.get_or_create(
+                       course_id=course_id,
+                       student=user,
+                       module_state_key=module_state_key,
+                       defaults={'state': '{}', 'module_type': 'problem'},
+                 )
 
     try:
         pmd = PsychometricData.objects.using(db).get(studentmodule=sm)
@@ -329,7 +331,11 @@ def make_psychometrics_data_update_handler(course_id, user, module_state_key):
             return
 
         pmd.done = done
-        pmd.attempts = state['attempts']
+        try:
+            pmd.attempts = state.get('attempts', 0)
+        except:
+            log.exception("no attempts for %s (state=%s)" % (sm, sm.state))
+
         try:
             checktimes = eval(pmd.checktimes)                   # update log of attempt timestamps
         except: