I've checked everything and it looks great

Not sure what could be wrong? the code is fine
I think that you may be refering to the bottom bar at the end of your default style forum, It seems wider?? Aparently its the same on all VBulletin default themes, the bottom bar is wider and goes right up to the white border,
Take a look at a screenshot i did from the VBulletin.com site, and you'll see what i mean, I know they don't use my menu's on there, well not at the moment