Well, looking at the source code, right after the 'large' box (where it says "Playstation 3", "Wii"), you are closing the tbody and table and then you start another table. I'm not sure why you are doing that, but that is where the problem is occuring (you aren't closing the tbody and table tags between any other sections).
Well, that's odd. I'm guessing the designer did that. Anyway, what turned out to fix things was taking out the sub-forum stats that display(cyb sub forum manager). The big box, which i thought was the normal size, was actually being slightly stretched due to the sub-forum stats being crammed in.