Couple of suggestions
There doesn't appear to be a "remember me" function which most forums have to keep you logged in. It's a great little feature and would benefit these forums.
When I go directly to a sub forum by typing the url in the address bar, I always get redirected back to the main forum page. This is surprisingly annoying!
"Sometimes free software isn't free and sometimes free software isn't free. Sometimes it's both free and free and sometimes it's neither free nor free!
Why is this so hard to explain" - Me