有IE7和浮动元素的问题（当然）

I'm working on a site that has a wrapper element, with a left and right sidebar, each floated within the wrapper. The left sidebar (which contains navigation) is clearing the right sidebar and pushing it to the bottom for some reason. I've tried fixing it in about 50 different ways. I originally thought changing the size and or margin would help. It didn't. I tried the 'display:inline' fix to no avail. I've tried a ton of other tweaks but I can not get it to work. You can view the site at www.ibgs2010.org and the css is www.ibgs2010.org/css/style.css (I'm trying to use a IE7 specific stylesheet to fix it). If anyone can help, I'd really appreciate it. I've burnt about 3 hours today just trying to fix this one little issue.I'm working on a site that has a wrapper elemen