I've got my page displaying as I'd like it to in IE5/6 and Opera. IE5.5/mac and Moz 1.1 give something a little different. The boxes on the right that contain <OL>s have a gap between the header box and the main box in Moz. Clearly this is something to do with the CSS of the <ol>, but I'm not sure what.
IE5.5/mac renders a gap between all of header boxes and the main boxes (big boxes and wee ones) and I've no idea why.