There is an issue with ASP.Net 2.0 Menu control, when viewed with IE8. I was really stumbled at it, as it was working perfect in my dev environment but gave me a surprise when i pushed it to deployment. Here are some stuff and fixes related to it.
Official: http://support.microsoft.com/kb/962351
Blogging: http://blogs.msdn.com/giorgio/archive/2009/02/01/asp-net-menu-and-ie8-rendering-white-issue.aspx
http://weblogs.asp.net/bleroy/archive/2009/03/23/asp-menu-fix-for-ie8-problem-available.aspx
