Re: have no idea...
This just happened to me this week. It kept doing it after a couple of restarts. So I shut down and took the RAM out and let it sit for a few minutes, put it back in and I restarted.
It worked great after that, hopefully it will work with you too.
Check out my Counter Strike:Source servers:
***THE DYNASTY***: 220.127.116.11:27015
*** GUNGAME ***: 18.104.22.168:27015
*** SOCCER ***: 22.214.171.124:27015