Hey~
As Tom mentions, there were problems with machines as they upgraded from Beta 2 of ASP.NET 2.0 to RTM had problems. I believe that we are currently working on a Knowledge Base article to discuss some of the known issues, though I can't promise anything. There is another issue if you possibly are running a 64-bit version of the OS & ASP.NET 2.0 - this doesn't work (known issue.)
If you could share a little history as to how you got to this point, then I might can help you a bit further -
Thanks and hope that helps,