[Django-users] reauest.session[] not working.

My view:

@login_required
def list(request):
     user = User.objects.get(pk=request.session['user.id'])
     # Handle file upload
     if request.method == 'POST':
         form = dataFileForm(request.POST, request.FILES)
         if form.is_valid():
             newdat = dataFiles(datafile = request.FILES['datafile'])
             newdat.user_id = user
             newdat.save()
             # Redirect to the document list after POST
             return HttpResponseRedirect(reverse('tilda.myapp.views.list'))
     else:
         form = dataFileForm() # A empty, unbound form'''
     # Load documents for the list page
     datafiles = dataFiles.objects.all()

     # Render list page with the documents and the form
     return render_to_response(
         'myapp/list.html',
         {'datafiles': datafiles, 'form': form, },
         context_instance=RequestContext(request)
     )

Under Windows7, using Python 2.7.5, with MySQL, this works after login,
showing a list of files already uploaded and the form to upload a new
file.
I have now moved the app onto Ubuntu 13.04, using Python 2.7.4 with
Postgres 9.1 (in reparation for a test deployment to Heroku), using
vrtualenv. Following login, when I try and access this page, I get: Key
Error at myapp/list: 'user.id'.
I cant find a reason for this not working, can anyone help?



Cheers, Nigel
07914 740972