Right, i would first off either change the background colour or the forum table background, in my opinion its to white.
Also the logo seems a little unprofessional so would reconsider changing that and incoroprating a image or few into it or something.
I think the live help and search function graphics in the forum topic looks abit in your face so i would probably remove them so the forum is even in sizes etc.
I like the top of each forum with the strip stating what the board is about though and i like the top nav
Well done