Please help. Browser issues!

I have been running my site NerdBlend for a few weeks now. Link: here. I think my site looks great on Firefox and Safari, the only two browsers I use, but I recently took a look at it in IE7 and the right side sidebars look like garbage.

Does anyone know what I can do to fix this? I’ve tried everything I can think of by adjusting sidebar.php. By the way this is a customized version of StudioPress. I’ve even tried pasting the original, unedited code back into sidebar.php and that didn’t fix the issue.
PLEASE HELP! Thanks…