Forum Moderators: not2easy
It could be any of several things working against each other.
Hopefully, we can offer a proper fix without too much hacking. Designing in any browser other than IE is the best place to start. Then you hack in some IE specific fixes IF they are needed.
My recommendation is to strip the HTML and CSS down to the problem itself. If the fix is not found during this process, post the test ready code that replicates the problem and we will look at the options.