now did you hand code all of this, props to you if you did. But as far as suggestions I would suggest that you not use the frames that you scroll and instead just use the whole page, but that's just my own personal preference. Either way if you did this all by hand well done, because I know how tedious that can be.
dont force the banner to stretch (decrease the height, keep the width the same). it's ugly imo. you don't need to number the nav bar links either.
on your forums, you 1. don't need to keep the image as a gif (since it makes your banner look worse) if you know how do edit phpBB; and 2. if yo don't want to change the banner on the forums, you can add the background to it, so it doesn't have rough edges