VS2005 and ASP.NET: Can't start my debugger

For the record, I have absolutely NO IDEA what's going on here. But with luck this solution may work for you. I'm playing around with ASP.NET web services and I was getting this error from VS2005 (I was getting this before and after SP1 installation):

"Unable to start debugging on the web server. An authentication error
occurred while communicating with the web server."

Searching on the error produced links to proposed solutions that didn't work for me. This was the only official Microsoft link I found that addressed the error message.

So now I know basically that IIS was having trouble starting my debugger. So I thought, hmmm, let's just try this without debugging. Ctrl-F5 and everything comes up as expected. I closed the new browser window (I'm working on a service) and then hit F5...just to see what would happen. And LO! Up comes my debugger. I set a breakpoint, ran the service, and hit the breakpoint.

I can only assume that a VS2005 setting got munged and Starting Without Debugging fixed it. But I just don't know. Good luck on this one...there seems to be many paths to the same error message.