I am playing Halo 3 on my campus with an Open NAT (or so the XBox says) yet I am unable to connect to games with a friend of mine who lives back home. His XBox says he is using an Open NAT as well, yet I can neither join his game or he join mine, we simply get an error message saying Cannot join because of network problems. You have an Open NAT. I am however able to play online with another friend of mine who lives off campus. My friend back home is using a wireless internet system instead of a hard connection like mine and my friend off campus. Any ideas on how to fix this?