Is it possible to extend the Node model in a module?

Environment:

Request Method: POST
Request URL: http://127.0.0.1:8000/questions/ask/
Django Version: 1.2.1
Python Version: 2.7.0

Traceback:
File "C:\\Python27\\lib\\site-packages\\django-1.2.1-py2.7.egg\\django\\core\\handlers\\base.py" in get_response
  100.                     response = callback(request, *callback_args, **callback_kwargs)
File "C:\\dev\\epon\\forum\\modules\\decorators.py" in __call__
  52.         res = self._callable(*args, **kwargs)
File "C:\\dev\\epon\\forum\\modules\\decorators.py" in <lambda>
  30.                 self._callable = lambda *args, **kwargs: fn(origin, *args, **kwargs)
File "C:\\dev\\epon\\forum_modules\\akismet\\startup.py" in wrapper
  53.         return origin(request, *args, **kwargs)
File "C:\\dev\\epon\\forum\\views\\writers.py" in ask
  80.                     ask_action = AskAction(user=request.user, ip=request.META['REMOTE_ADDR']).save(data=form.cleaned_data)
File "C:\\dev\\epon\\forum\\models\\action.py" in save
  128.             self.process_data(**data)
File "C:\\dev\\epon\\forum\\actions\\node.py" in process_data
  23.         question.save()
File "C:\\dev\\epon\\forum\\models\\node.py" in save
  378.             super(BaseModel, self).save(*args, **kwargs)
File "C:\\Python27\\lib\\site-packages\\django-1.2.1-py2.7.egg\\django\\db\\models\\base.py" in save
  435.         self.save_base(using=using, force_insert=force_insert, force_update=force_update)
File "C:\\Python27\\lib\\site-packages\\django-1.2.1-py2.7.egg\\django\\db\\models\\base.py" in save_base
  479.                 self.save_base(cls=parent, origin=org, using=using)
File "C:\\Python27\\lib\\site-packages\\django-1.2.1-py2.7.egg\\django\\db\\models\\base.py" in save_base
  518.                         for f in meta.local_fields if not isinstance(f, AutoField)]
File "C:\\Python27\\lib\\site-packages\\django-1.2.1-py2.7.egg\\django\\db\\models\\fields\\__init__.py" in pre_save
  257.         return getattr(model_instance, self.attname)

Exception Type: AttributeError at /questions/ask/
Exception Value: 'Question' object has no attribute 'test'