1) The bg color of the arrows .gif isn't the same as the nav table bg color. It is even more obvious when you click on a link and that the arrow appears next to the section title. Running IE6. Same with Moz.
2) With Mozilla your links are underlined with the default link color.
3) I am not supportive of pop-ups at all but you should have one for your 'designed by' link.
4) I am not sure that the borders of your page are useful. Solid borders would probably look better.
5) The page goes down and down and... but there is no content at the end of this scroll (Moz and IE).
Hope I helped