You coded this in a WYSIWYG editor, I take it. Lots of FONT tags that don't have anything in them (or only images, in which case there's still no need for the tag), and a bunch of unnecessary tables as well (this site could have been done with only one table). Nevertheless, as far as table-soup goes your code is pretty clean; I don't see any obvious errors. You should put blank summary attributes on your tables, but that's the only other thing I can think of.
I see the problem, though. What you need to do is add a fourth table row, between your content and footer tables. This row doesn't need to actually contain anything; it just has to have two cells of the appropriate colors. Do not specify a height on it, and at least in theory it should stretch to accommodate the window.
Also, looking at your CSS, you have a rule for a tag with a class of "body", but no tags with that class are in the document. You should probably change .body to body; I think that is what you were trying to do (you may want to make it "body, td" just to make sure Netscape4 will catch it). This will also allow you to get rid of most of those FONT tags, which should help your bandwith usage.