This is a very small project (my css/html knowledge is not very good).
My blog and my forum works good in Firefox but they have some graphic problems on Internet Explorer.
You should fix them. I think the problem is CSS related (but it's better you check by yourself: [login to view URL] and also check the forum link).
I use WordPress and Simple Press Forum.
You can ask for the page you need (or you can download them because they are Open Source) and fix them.