Sorry it took so long, maybe my initial post wasn't clear enough. The major problem stems from a content element larger than the available screen (after the leftmenu).
On IE (at least - I havent got past Firefox and IE yet) a wide element like a picture or table will be pushed below all content in the left menu. Using most methods of float-based 2-Column layouts. If I use absolute positioning I can get it to work(ish) but the footer goes all over the place.
You can replicate the situation using your previous example just place a short sentence of normal text in the "content" div, then immediately following that place a huge image or table (maybe make the leftMenu content a bit larger too)
The picture will be pushed until level with the base of the left content.
<p>blah blah blah</p>
<img src="/image/image.gif" width="2000" />
Even stranger is that sometimes the "blah blah blah" will disappear (in IE again)... But thats another problem.