No to sound unsympathetic, but why in the world would you install pre-beta
software on your production PC?
I don't have a specific quick fix for your problem, but if I were in your
situation, I'd plan on uninstalling Whidbey, then reinstalling Visual Studio
.NET 2003. Whidbey uses a very different system for local web server support
for ASP.NET applications from that employed in VS.NET 2003, so I would
*guess* that Whidbey highjacked the mappings.
You may well get better advice in the private Whidbey newsgroups, or from
the links below. If you downloaded Whidbey from your MSDN subscription, or
obtained it at a seminar or presentation, you should have received
documentation on how to join the private Whidbey newsgroups. My May DVD came
with this link for feedback:

http://msdn.microsoft.com/vs2005/currentreadme/default.aspx

Where "A direct feedback mechanism is available online at
http://msdn.microsoft.com/whidbey. We encourage you to provide us with your
comments and requests."