If you mean the blue nav bar, then you may be better off creating a background image that replicates the blue bar and sticking that in the body tag.
Trying to get a table to reach the bottom of the screen with a height=100% can - I think - be achieved in some Windows versions of IE, but implementation on the Mac is somewhat less than perfect. You can end up with scroll bars that give you an extra screen or two's depth.
BTW, the button 5, button 6 and button 7 rollovers looked screwed - GL's put /*CMP*/ before the first parameter in each bit of javascript - you may want to fix that!