Halo 3 multiplayer problem

[MrTom]

Well i was all excited to get playing, but for some reason I can never get past the lobby (where you see/talk to other players) before it boots me back to matchmaking options. Anyone got any ideas?

[Mekon]

Have you checked yout NAT settings?

http://www.xbox.com/en-US/support/connecttolive/xb...

[MrTom]

update: It seems my complete disk is fubar, nothing actually works. Tested my box with other games and its fine.