Entering my CD-Key (from the back of the instruction manual for Silent Hunter-Wolves Of The Pacific) when I'm trying to play online results in an "Invalid License Key" message. I'm using ZoneAlarm and have given Silent Hunter access to the Trusted and Internet Zones. What am I doing wrong? Could these issues be linked? (I read somewhere about problems using ZoneAlarm and a recommendation to use Windows Firewall instead) Thanks for your help.