Hi,
Looks like you have figured out the problem as i don't see anything wrong in that page.
Just one thing grabbed my attention, in the bottom-a module position, the links are almost invisible because the link colors are so dark. You should brighten those links by adding this CSS rule: (to any CSS file)
#bottom-b a { color:#bbb;}
#bottom-b a:hover { color:#ff0000;}
Regards.