When attempting to debug a web application running on its web server, VS 2010 always shows the, "Break point will not be hit, no symbols are loaded" message.  All machines are within my AD domain.  The workstation is running Windows 7 Pro x64.  The server is running 2008R2 Enterprise on a Hyper-V host.  After wasting several days hunting this down I found the following:

The PDB file is not getting copied to the Temporary ASP.NET directory where the debugger has loaded the DLL from.  If I attempt to load the symbols from the PDB in the URL bin directory, I get the "No matching file found" message.

If I copy the offending "No matching..." PDB from the URL bin directory to the Temporary ASP.Net Files directory, I can attach to the process and the symbols load just fine.

I do not have this problem when debugging a site or service on a Windows 2003 server hosted on the same Hyper-V host.

How do I kill this little gremlin?