blog.elsdoerfer.name

If you're seeing the above error, possibly during a reverse() call, and possibly involving the django.contrib.auth.views.template_detail view, make sure none of your application directories has a file named templatetags.py - Django actually requires this to be be a package/directory.

Oh, and on a more general note: Not forgetting the .pyc files when deleting modules will greatly reduce the time needed to  debug cases like this