Raven Shield CD KEY SERVER NOT RESPONDING HELP!!!

[iron mike]

I have a purchased version of the game. No firewall or router. Just a plain ole' PC with a direct cable connection. Everytime I try to get onto a server, I get the message

CD KEY SERVER NOT RESPONDING TRY LATER

IT is driving me crazy. I see lots of people have run into this... can anybody guide me through a fix?

Mike