I've got a few headers, and when you click on them, it toggles the information below it to either show, or hide it accordingly. All it does basically is set the position of the div to absolute and the left attribute to -5000px to nudge it off the page.
Problem is, whenever you run this code, it's cutting off the container div completely, as well as the area list that's being floated.
I don't have access to an FTP here unfortunately, and it's got loads of PHP so it'd be a bit of a nightmare to post the code anyway, but hopefully I've given enough information to give a jist of just what's going on. If not, I'll happily mock up some basic test code for it.