There is a problem with Xbox live which is effecting both the website and the consoles.
Not everyone is getting this error however.
The error is when you try to join an Xbox Live Party or join a multiplayer game. You will be unable to connect to the party and you will get signed out at the menu of the game. This is not effecting everyone though.
Microsoft have said that they identified the problem on march 24th but it seems they still do not have a fix.
Modern Warfare 3 was having Double XP while this was all happening, so to compensate for the lost time Double XP has been extended
Source - https://twitter.com/#!/fourzerotwo
If you ARE having trouble then turn off your xbox for half an hour then try connect again
Last edited by Ed; 03-26-2012 at 05:08 AM.