Xbox Live Error Message

hello. i would just like to address a problem and hope that someone would recognize and help me with.

I was matchmaking on Halo 3 the other day when all of a sudden I was disconnected from my match with the confrontation of the message that read something like this; "you have been logged out of Xbox Live from your console because it was logged onto from a different console...Press A". I've been pondering over this for a couple of days and wasn't able to figure out the problem. I was afraid that someone had hacked into my account. Could this be so?

by the way, my account was never used on another console before. plus I was experiencing connection problems.

plz help. and thanks in advance

nope but i would change ur password incase, because he would have to know ur windows live id and once its recoved somewhere else you must enter it to recover it back.

Sounds like a weird mixup, but can never be too safe. You good though dont loose sleep/

Also if u were running MSN through xbox at the time, somone may of turned on the computer which auto signs u in and that could be the message. If thats not the case refer to above