It's a weird one, because it doesn't affect everybody the same way. I just loaded the game up and had my **** handed to me a couple of times, but it just works here! If I had to put money on it, I'd bet on the anti-cheat software (Vanguard) they require. When the game takes 1.7GB (+ level downloads), but the anti-cheat software is 20GB+!!!
Anyway, I'm glad it's working now, and don't forget to secure your system after you've played it!
*I have a serious aversion to opening ports and using DMZ unless it's absolutely necessary.
**Some players claim to have gotten around the issues by using a VPN client on the games machine!