Question : RPC/HTTP won't accept password on Exchange 2007 unless the Default Web Site is restarted

I have a single Exchange 2007 Server running on Server 2008 x64.  The server has been running fine with all components working properly.  I had Outlook Anywhere setup on the server with a wildcard cert *.domain.com which was working great.  AutoDiscover was working great in Outlook which would configure the Exchange Server settings automatically using NTLM authentication.   Now, out of the blue, I started getting prompted for a password on every account repeatedly even thought the password is correct and the the account is set to never expire in AD.  The server event viewer shows no signs of any problems with the server.  The only way I've been able to get it to accept the password is to go into IIS 7 on the server and stop the Default Web Site and start it again.  Outlook almost immediately accepts the password and then connects.  About 10 minutes later if I open Outlook, the password prompt returns and doesn't accept the password and then I have to stop the site again and restart it.

Answer : RPC/HTTP won't accept password on Exchange 2007 unless the Default Web Site is restarted

Problem resolved.  Installed SP2 for Exchange 07 and the issue resolved itself.