links not working in firefox

hey /prog/,
I have a problem: my site www.matthaspictures.com dosent work in firefox. well, everything works except for the links in the tabs. they turn into plain old text and i dont know why. it works perfectly in IE, but has the same problem in safari.

I didnt use a page generator of any kind, hand coded the whole thing from scratch. any idea whats going on? thanks so much!

In all seriousness, you should really rewrite this page. It's horrid to say the least. Forcing people to only view in Internet Explorer 7 is not a good idea. (Despite IE being the browser with the biggest market share.) If say someone with Firefox, Opera, Safari, etc. come to check your site and see that it breaks in their browsers, they won't be too willing to launch IE just to see your site and you'll lose a lot of potential viewers this way.