Unable to start debugging on the web server. Unable to connect to the webserver

Unable to start debugging on the web server. Unable to connect to the
webserver

I am running Visual Studio 2008, IIS 7.5 on Windows 7 x32. I am able to
run the ASP.NET web site in IIS 7.5 without debugging just fine, but when
I press F5 to debug it, I get:
Unable to start debugging on the web server. Unable to connect to the
webserver. Verify that the web server is running and that incoming http
requests are not blocked by a firewall..