Just finished some lengthy debugging of a layout that was breaking in all versions of IE I have access to (6, 7 and 8b2). OS is Windows Vista Business, if that matters.
I figured out how to bypass the issue but not quite sure what to make of the cause of the error. The layout is a pretty standard fixed-width with a header, a content section split into 3 columns, and a footer. Following the 3 columns in the content section is an IMG. The layout works fine in all browsers I've tested. However, if I add a simple class (.red {background-color: red}) to elements within the #footer via JQuery the three column layout breaks in the previous containing DIV in all versions of Internet Explorer. However, I can alter the background-color of #footer elements via css () method or directly adding the class in the HTML itself and all remains fine within IE. If I move the IMG outside the 3 column container, and between the content DIV and #footer DIV, these IE errors no longer occur. I'm not sure if this is a bug (known or unknown), but examples can be seen at: http://www.sportsamerica.com/testjquery/withJSh2.html