Djangobb problem
There are two obvious reasons to why this might happen:

djangobb_forum is not on your Python path
There is no __init__.py in the djangobb_forum folder

If the code says from djangobb_forum import ... then you need to have the parent folder of djangobb_forum on your Python path.
I've installed Djangobb app on my server (Debian, mod_python) by cloning original source. The only things I've changed is database options in settings.py. All needed components are installed - syncdb query was executed right.
But, when I'm trying to enter on my forum, it returns me error:

ImproperlyConfigured: Error importing middleware django_authopenid.middleware: "No module named djangobb_forum.subscription"

I've checked - djangobb_forum/subscription.py exist, so I don't know what can be wrong.
Maybe someone had problems like that and know how to fix it?
Sorry for my english.