I'm not surprised. I haven't dealt with any browser but chrome and firefox. Also, IE8 does not support all the gradients etc. I'm gonna install IE9 now and have a look
Looks as though it's not supporting the styling of buttons and is adding a border around images that are a link. That can easily be fixed (especially the first one)
EDIT: Should have fixed the second one. Can you have a look? IE 9 is taking ages to install