Hello... I noticed last night that I can't join my friends' games, or accept their invites. In fact, I don't even see their invites in my message box when they say they've sent them on my 360. But when I go on Xbox.com, I can see the messages, as well as the invites... they can't join me either. Any idea why this could be happening? I reset my router and restarted my 360, but it's still going on. Also, according to Modern Warfare 3, my NAT is 'open', so I'm not sure what happened. Thanks.