title: Attribute Error When UserProfile Object is Added
body: <p>I recently migrated  Django 1.7.1 to Django 1.9.1 . If I try to add a UserProfile to a new user (mapped one to one), I get an attribute error. </p>
  
  <pre><code>AttributeError at /admin/coffee/userprofile/add/
  'bool' object has no attribute '_committed'
  Request Method: POST
  Request URL:    http://127.0.0.1:8000/admin/coffee/userprofile/add/
  Django Version: 1.9.1
  Exception Type: AttributeError
  Exception Value:    
  'bool' object has no attribute '_committed'
  Exception Location: /tmp/idly/lib/python2.7/site-packages/django/db/models/fields/files.py in pre_save, line 309
  Python Executable:  /tmp/idly/bin/python
  Python Version: 2.7.10
  Python Path:    
  ['/Users/nlokesh/idly',
   '/tmp/idly/lib/python27.zip',
   '/tmp/idly/lib/python2.7',
   '/tmp/idly/lib/python2.7/plat-darwin',
   '/tmp/idly/lib/python2.7/plat-mac',
   '/tmp/idly/lib/python2.7/plat-mac/lib-scriptpackages',
   '/tmp/idly/Extras/lib/python',
   '/tmp/idly/lib/python2.7/lib-tk',
   '/tmp/idly/lib/python2.7/lib-old',
   '/tmp/idly/lib/python2.7/lib-dynload',
   '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7',
   '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-darwin',
   '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-tk',
   '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac',
   '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac/lib-scriptpackages',
   '/tmp/idly/lib/python2.7/site-packages',
   '/Library/Python/2.7/site-packages/pip-7.1.0-py2.7.egg',
   '/Library/Python/2.7/site-packages',
   '/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python',
   '/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/PyObjC']
  </code></pre>
  
  <p>Relationship between User and UserProfile in <code>models.py</code>:</p>
  
  <pre><code>user= models.OneToOneField(User, null=True)
  </code></pre>