Hey I have Xbox as well, and when I got a new one it wouldn't let me download the necessary update when I was on campus. The error code was 80151103. It wouldn't let me download my profile or connect to xbox live...anyway Microsoft were bloody useless, so if you ever get it, just go to a friend's house (off campus) with an open nat type, and it worked there! Now I don't have any problems, aside from trying to connect with other people with a Strict Nat Type :/
Feel free to add me on xbox, be cool to know other Lanc Uni people with Live :P PickVanCleef is my gt :P