IE 5 CSS Issue

I recently started tweaking wordpress to fit my design. After a few days of figuring out how it works I’m fairly happy with it. Only problem is in firefox, camino, and safari the page align is fine. in IE 5 it’s a bit off and I cant figure out why.

www.monunmentsinking.net is the site I’m working on and if anyone could point me in the right direction of why in IE the page margin shifts a few pixels down and in the other browsers it doesn’t I’d be very greatfull.