Okay, I have a FLASHED xbox 360. I downloaded Halo 3 and burned it on to my disk. After I did that, I went to matchmaking and it says " I need to be signed in to xbl. " I click the middle guide button and I'm signed on. I can only be in a "Local" Party for H3. Can someone help me getting it to recognize me that I'm on XBL or did I just download a corrupt halo 3?