If you haven't got these already. This will get you them in about 10 seconds.
Log onto the CoD: Elite site. DELINK your gamertag from the account.
Then RELINK the gamertag to the account.
Go onto the xbox application for Elite and have a quick browse around career stats or whatever floats your boat.
Go online to the main menu on MW3. And go to your callsign.
Give it a few seconds and you will get the notification saying "NEW" beside your call sign.
Enjoy.