If I were in charge of the forum, this is what I would change (bearing I have limited knowledge on this :P)
I'd change the blue/turquoise (sp) background that's around the edges, it's abit garish still, i'd make it somewhat darker
Also, the navbar area is huge, I assume due to the "click here to find out how to advertise" (or words to that effect)
Also, just a personal preference, i'd align=middle the mini logos next to the navbar menus.
I did a l33t MSPaint example of what I mean (...I'm REALLY tired, so excuse the basicness of it :P)
This is the same background, with a darker shade of that blueish colour
(This is just a personal preference thing, but it isn't as odd looking as the current colour, no offence! :P)