IE7 & CSS

Hi, I’ve got a site at http://www.escapepodx.com. I’m using a modified version of the Black Hat theme, and it looks great in Firefox, but when I put it into Internet Explorer 7, the individual tabs in my menu bar go to a block display instead of the default inline display. I’m sure that the issue is IE7 misreading my CSS, but I’m not sure how to fix it. Any thoughts?