title: Can't perform data migrations using django 1.5 Custom user class
body: <p>I have many applications with historic south initial migrations, which i wanted to convert to django 1.5 applicable. So i swapped out all orm['auth.User'] references in migration files with custom ones, but when i try to run those migrations i get following error:</p>
  
  <blockquote>
    <p>Error in migration: django_notify:0001_initial
    KeyError: "The model 'customuser' from the app 'profiles' is not available in this migration."</p>
  </blockquote>
  
  <p>The migration in question is this:
  <a href="http://bpaste.net/show/2CwaYrlNifNTd5gcHUfK/">http://bpaste.net/show/2CwaYrlNifNTd5gcHUfK/</a></p>
  
  <p>My custom User class is:</p>
  
  <pre><code>class CustomUser(AbstractUser):
      image = models.ImageField(_('Image Field'), upload_to='user_images')
  </code></pre>
  
  <p>I am also unable to convert my'profiles' app to south using convert_to_south command. I get the following error:</p>
  
  <blockquote>
    <p>Creating <strong>init</strong>.py in '/Users/tejinder/Projects/basidia/apps/profiles/migrations'...</p>
    
    <ul>
    <li><p>Added model profiles.CustomUser</p>
    
    <ul>
    <li><p>Added M2M table for groups on profiles.CustomUser</p></li>
    <li><p>Added M2M table for user_permissions on profiles.CustomUser</p></li>
    </ul></li>
    </ul>
    
    <p>Created 0001_initial.py. You can now apply this migration with: ./manage.py migrate profiles</p>
    
    <p>CommandError: One or more models did not validate:
    auth.user: Model has been swapped out for 'profiles.CustomUser' which has not been installed or is abstract.</p>
  </blockquote>
  
  <p>What could have been gone wrong? Thanks in advance.</p>