find the HTML error in this page that renders it wrong in IE but not in Firefox

The website [[login to view URL]][1] is rendering correctly in Firefox 3, but when viewed in Internet Explorer 8 (and probably other IE versions, but I didn't check), the main center content gets pushed down underneath the left-hand column. I'm sure it's a very simple change (probably just the addition of a single tag somewhere) to fix it, but I can't find it myself. Tell me what I need to change, to make the page render correctly in IE8 the way it does in FF3 :) Note, we cannot give out ftp access to the site itself. But you can save a local copy by doing "View Source", copying all the HTML, putting it in a local file, and then adding a BASE HREF=<[login to view URL]> tag in the HEAD section. Then open the local file and the file will load the css, images, etc. from the beanonline website. Then you can make edits to see if you can fix the layout so it works in IE8. (Of course, make sure it still renders properly in Firefox as well.) This is so simple, you might even be able to find the answer before bidding on the project. So in your bid, please say whether (a) you think you *might* be able to find the answer if I accept your bid, or (b) you have already found the answer, and you'll tell me if I just give you the money :)