[1.0.X] Fixed the tests from [9438] to work consistantly across databases. In...

[1.0.X] Fixed the tests from [9438] to work consistantly across databases. In particular, it was failing on newer versions of PostgreSQL after [10586]. Backport of [10626] from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.0.X@10627 bcc190cf-cafb-0310-a4f2-bffc1f526a37