Environment:

Request Method: POST
Request URL: http://127.0.0.1:8000/testone/
Django Version: 1.2.7
Python Version: 2.7.2
Installed Applications:
['django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.sites',
 'django.contrib.markup',
 'mydb.movies',
 'django.contrib.admin',
 'mydb.databrowse',
 'registration',
 'reversion',
 'haystack',
 'hitcount',
 'debug_toolbar',
 'chronograph',
 'change_email',
 'favorites',
 'blog']
Installed Middleware:
('django.middleware.common.CommonMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.middleware.transaction.TransactionMiddleware',
 'reversion.middleware.RevisionMiddleware',
 'breadcrumbs.middleware.BreadcrumbsMiddleware',
 'debug_toolbar.middleware.DebugToolbarMiddleware')


Traceback:
File "C:\Python27\lib\site-packages\django\core\handlers\base.py" in get_response
  100.                     response = callback(request, *callback_args, **callback_kwargs)
File "c:\development\python\mydb\movies\views.py" in testone
  1664. 		if form.is_valid(): # All validation rules pass
File "C:\Python27\lib\site-packages\django\forms\forms.py" in is_valid
  121.         return self.is_bound and not bool(self.errors)
File "C:\Python27\lib\site-packages\django\forms\forms.py" in _get_errors
  112.             self.full_clean()
File "C:\Python27\lib\site-packages\django\forms\forms.py" in full_clean
  269.         self._post_clean()
File "C:\Python27\lib\site-packages\django\forms\models.py" in _post_clean
  320.         self.instance = construct_instance(self, self.instance, opts.fields, opts.exclude)
File "C:\Python27\lib\site-packages\django\forms\models.py" in construct_instance
  51.             f.save_form_data(instance, cleaned_data[f.name])
File "C:\Python27\lib\site-packages\django\db\models\fields\__init__.py" in save_form_data
  416.         setattr(instance, self.name, data)
File "C:\Python27\lib\site-packages\django\db\models\fields\related.py" in __set__
  325.                                 (instance._meta.object_name, self.field.name))

Exception Type: ValueError at /testone/
Exception Value: Cannot assign None: "Film.studio" does not allow null values.