Browser compatibility issues

My site (http://firstclassnoise.com/) looks fine in firefox, but not in IE8. I’ve run this validation check: http://validator.w3.org/check?uri=http%3A%2F%2Fwww.firstclassnoise.com&charset=%28detect+automatically%29&doctype=Inline&group=0&user-agent=W3C_Validator%2F1.2
I’m guessing one of those is the big problem, I’m not a pro at any of this stuff, very self-taught.
Any help would be appreciated! Thanks.