Ok. 2 things you can check.
First, I dont use Norton so I'm unfamiliar with the process it uses to "allow" programs to access the internet. I'm assuming you have a list of programs that are allowed. Sometimes when you update Aces High, the firewall doesnt allow it anymore. You have to remove it from the list of allowed programs and then add it anew. Perhaps you already did this, if so I'm sorry, just typing things out as I think of them.
Second, check to make sure Windows didnt somehow turn on its firewall. It happens sometimes. Happened to me once and it took me 3 days to figure it out, since I never use it.
I'll bang my head against the wall and see if I can think of anything else. I know there must be more ways to cause that.
