[1.1.X] Fixed #12506 - 'lazy' fails when there are multiple expected classes with the same method

  
Thanks to Alex for report and patch

Backport of r12104 from trunk.


git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.1.X@12105 bcc190cf-cafb-0310-a4f2-bffc1f526a37