VPN's and System Shock 2

[Reacon]

So a couple of my friends convinced me to try out System Shock 2 and play coop with them. After literally 4 hours of googling, trying, retrying, reinstalling, trying difference softwares, try different versions of softwares, and finally, different versions of the game, I've come to the conclusion that I am overlooking something.

It is not server sided, as my other friend can connect to the host perfectly. I, however, cannot. Currently we're using Hamachi 1.0.1.5 at my suggestion. Any later versions end up crashing or just outright not working. I've tried Tunngle with no avail, and a couple others. Obviously it is not the VPN software. I've made sure network adapters for the VPN software are top priority, and I've forwarded a crap-tonne of ports that they recommended; all test positive but the problem persists.

They can ping me. Both through my VPN IP and my public. I can ping them, also. Windows Firewall is completely OFF, and I have nothing but Avira guard running. There must be something I'm missing.

Also note that I'm pretty tired atm. Sorry both for bad wording in my two paragraphs, and making you read this sentence of apology :) . Feel free to ask questions... though I likely won't answer them for another 16 hours because of sleep+school.

Thanks.

Also: Lol, my first post in a few months. I would be more active if it weren't for those meddling kids UPS workers, and their damnable tech support!