In django.contrib.comments.views.comments.post_comment there should be a check for not manipulator.get_user().is_authenticated() before trying to do a login(). Otherwise the login fails with:
Traceback (most recent call last):
File "c:\django\django\core\handlers\base.py" in get_response
74. response = callback(request, *callback_args, **callback_kwargs)
File "c:\django\django\contrib\comments\views\comments.py" in post_comment
222. login(request, manipulator.get_user())
File "c:\django\django\contrib\auth\__init__.py" in login
53. request.session[BACKEND_SESSION_KEY] = user.backend
AttributeError at /comments/post/
'User' object has no attribute 'backend'
# If user gave correct username/password and wasn't already logged in, log them in
# so they don't have to enter a username/password again.
if manipulator.get_user() and not manipulator.get_user().is_authenticated() and new_data.has_key('password') and manipulator.get_user().check_password(new_data['password']):
from django.contrib.auth import login
login(request, manipulator.get_user())
