I'm having an issue getting the django.contrib.auth unit tests shipped with Django (1.2.3-3+squeeze1) to pass once an AUTHENTICATION\_BACKENDS is set. There are other posts such as [Unit testing with remote authentication](https://stackoverflow.com/questions/6243044/unit-testing-with-remote-authentication) and [How to Unit test with different settings in Django?](https://stackoverflow.com/questions/913549/how-to-unit-test-with-different-settings-in-django) in regards to fixing, however my tests are still failing with these suggestions. 

I've tried adding the following to my SetUP() and TearDown() methods to get around this.

```
from django.conf import settings
def setUp(self):
    self.old_backend = settings.AUTHENTICATION_BACKENDS
    settings.AUTHENTICATION_BACKENDS = None

def tearDown(self):
    settings.AUTHENTICATION_BACKENDS = self.old_backend

```

Anyone have any other suggestions for getting around this? Thanks in advance. 

Here is a paste of the tracebacks. <http://pastebin.com/xX4dmuzr>