I currently have four groups created on my site, two display the forums as expected and two do not. When a user selects the "Discussion' tab, there isn't any forums just the words 'Active Forums 4.1' (Which I wish wasn't there )

Any reason for this?

Has the group been approved?
Do the forums appear in the Active Social Control Panel when you view the group?

Hey, 
   I was having the same problem. I'm not sure if your issues with this is resolved. But i have resolved it by performing the following:

1. Go into Control Panel
2. Click Groups
3. Navigate down to Group Fourms section
4. In forum Name: enter a "Test Group" name
5. Enter "Test" for the description
6. Click Save
7. View the discussion tab in your profile, you'll notice the test group foum shows and previous group forums
8. Go back to control panel and delete the "test group" fourm you created
9. Wa La, its not working.

:-) Don't ask, this is just the first thing i did and its now working.

Thanks
Ricahrd