I messed aboute with it all last week and it should be so that anyone who is logged in, apart from banned traders can SEE the forums are there and what the threads are called and obviously they appear in the search. This is so people can see the extent of the classifieds section.
Only paid up members, traders and dignitories can access all sections and threads in there.
Nembies and Forum Users as they're called can only look in the sections and what threads are there and post new threads in the Parts wanted section.
Im sure I made it so that they can access the cars for sale section, maybe another custom permission affected it. There litterally a couple of thousand settings available per forum section!
Glad its sorted because thats how it was when we changed over and it should of been