Site Check- I am "this" close-I think

I have a one page prototype here (links wont work yet):

http://ucolk7.olk.uc.edu/research/index.html

CSS: http://ucolk7.olk.uc.edu/css5/st_layo2.css (underscore there, so: st_layo2.css)

This page validates as xhtml strict (W3C and WDG) and CSS compliant..

I have tested successfully(using browsercam and my own resources) in:

W2K

Explorer 6
Mozilla 1.3
Netscape 4.78 (shows as expected)
Netscape 6.2
Opera 7

Linux

Mozilla 1.1
" 1.3
Netscape 7

MAC

Explorer 5.2
Mozilla 1.1
Netscape 7
Safari 1.01

My problem is this:

In (W2k AOL 7.0 and Explorer 5), (Mac Opera 6.), and (linux-Konqueror)

My heading image does not show up... nor do the "quicklinks" on the left (which are includes, but so is the content, tabs, and footer). Can anyone point me in the right direction?

Thanks!!

Here are the results in browsercam:

http://www.browsercam.com/public.aspx?proj_id=6913