Problem with debugging ASP.Net application on IIS 7 on Windows 7

Few weeks ago I started using VS 2008 (Professional) with Windows 7 (Enterprise). When working with ASP.Net web applications I repeatedly stumble over the following error:

After opening a solution with a web project the first compilation and debug go perfectly fine. The second time I try to debug the solution I get the "Unable to开发者_如何学C start debugging on the web server. System call failed" error and solution does not start at all. When I try to debug it again it always shows the same error but sometimes the app actually starts but does not break on the server code at all.

Any ideas why this could happen? Thanks a lot for any suggestions.

(I use local IIS and run VS as Administrator)

Have you installed SP1 for VS 2008? I am using Win7 as well, and alot of the issues get magically resolved with a service pack. HTH.