Hi,
You will need to use the IE Developer Toolbar (press F12) to figure out what CSS is causing the layout to be messed up. Any changes you need to make to the CSS for IE to work correctly will need to be put in the IE7Specific.css file in your skin directory. IE7 can be very tricky but with a little bit of work, you'll get it figured out.
I'm going to move this thread to the Help With Design & Skins forum, as the problem isn't a bug in mojoPortal.
HTH,
Joe D.