I recall seeing this happen in some situations too. Does this happen at your site on all types of pages (wiki, contact us, stats, etc.) or just on some? Any other details you can provide will help to pin down what causes it. As far as I know, there isn't any set-up or patch that needs to be done by you.
The page layout method used in Andreas09 — luci's litecss — accomplishes a lot just being able to have a liquid no-tables layout that can adjust dynamically to wide content, etc. But since IE7 doesn't support the display:table CSS property (a step backward from even IE6), it's been a challenge to get it to work right.