python - Can't login to Django /admin interface

Question

First of all, I am a newbie. I'm running Ubuntu 11.04 which comes with Python 2.7 so I installed Python2.5 in different dir to run Django-Non-Rel on Google App Engine. I did the Guestbook tutorial and now I am trying to add admin access but when I type in correct username:password Django thinks its incorrect. It doesn't even work when deployed to GAE. If you know please poke me in the right direction.

I added:

AUTHENTICATION_BACKENDS = ( 
    'django.contrib.auth.backends.ModelBackend', 
)

INSTALLED_APPS = (
    ...
    'django.contrib.admin',
    ....
)

EDIT
I also added

url(r'^admin/', include(admin.site.urls)),

to urls.py in subproject directory.
EOEDIT

Then I created superuser and synced databases:

> python2.5 xxx-xxx-guestbook/manage.py createsuperuser python2.5
> xxx-xxx-guestbook/manage.py syncdb

Then ran the app and can't login. I created multiple different supersusers always with the same result.

EDIT2

Thanks everyone for trying to help but unfortunately neither of the offered solutions fixed the problem. I have decided to first learn Django on its own and then maybe switch to GAE Django-nonrel, so the question is not relevant anymore. Should I still pick one answer to give someone some points?

Answer 1

Waitting for answers