from: http://vaultofthoughts.net/ASPNETDebuggerTimeoutInWindowsVista.aspx

When I first installed Windows Vista with IIS 7 I have started to notice that ASP.NET debugger tends to time-out very often. Previously I hadn’t noticed such a behavior when I was using Windows 2003 with IIS 6. I really cannot tell if it was there or not, because I sometimes [...]