Hi there NsT.
First of all, thanks a whole lot for such a great mod. I've been testing it and seems really good, but I got some problems yesterday that you need to be aware of.
I created three tabs (let's call them A, B and C). Tab A includes categories 1, 2 and 3, Tab B includes 4, 5 and 6 and Tab C only contains category 7.
Category 1 and 7 are only visible to admins and mods.
Category 2, 3, 4 and 5 are visible to everybody (including guests).
Category 6 is visible to some usergroups (neither registered users nor guests)
When I use my own user (an admin) everything works fine, but when I test it using a registered user, the problems arise.
When clicking on Tab A, I get a login page saying that I'm not logged in (I am and I checked the "Remember me" checkbox) or that I don't have permissions to access that page.
The same happens when clicking on Tab C.
And when clicking on Tab B I can see categories 4 and 5, category 6 "title" row is shown but not the forums it contains. If I do not have permissions to access that category I would expect that it is not shown at all (that's the default behaviour of vB).
So, basically, it seems that you should check how are you handling user's permissions.
Thanks anyway and keep up the good work!
Edited to fix an stupid (and big) error