I've been banging my head against a wall for the best part of a day trying to resolve this issue. It's just a CSS issue which I thought I'd put out there in case someone knows straight away whats wrong.
I've done some Q&D checkout templating which is mostly right but there's an issue in IE6 (possibly 7) where the header image which shouldn't tile appears twice before logging in and in other weird instances. Sound familiar?
You can try to replicate it in Internet Explorer from here
. I know there are other smaller issues like layout of product pages but I'll get around to that (also listings could be more concise but the client wants it this way).