Could not start debugging on the web server

Hi experts,

There have been many posts regrding this issue, nevertheless I feel that my case is different.

I'm running an SQLServer database on a Windows Server 2003

When I start debugging the application everything is ok.
I start and stop the debugging many times, doing the same testing processing.
Suddenly I can not debug anymore and I get this message

"Could not start debugging on the web server"

If I try to run the app without debugging I get a message:

"Service Unavailable"

Retarting the web server wont help
Restarting the Visual Studio IDE creates an error message saying "Service Unavailable"


I need to reboot the server (!!!)  in order to be able to continue debugging


Please assist

Thanks,
Maf