Allow 48 hours for it to show.

wrong section buddy and yes like he said wait at least 48 hours

I got it in about 6 hours i think..
Takes up to 48 hours*

delete MW3 patch, re install and it should show up.

at me it showed up 20 min after the prestige

The 48 hour thing doesn't always work, what you need to do is go to COD 4 and play a couple online matches. THEN wait 48 hours and it will show up.

i heard that if you play some games online it will show but not to sure

Play a couple of games on cod4, delete your mw3 patch, & wait a couple of hours. It should work

well i personally have done this for many people and myself.. it "CAN" take up to 48 hours but heres the thing.. once you receive the 10th prestige you need to go play "AT LEAST" 1 FULL game so your name will return to the leaderboards. you can check by looking at the barracks and seeing that its showing your correct rank. once you have finished that then goto MW3 and check if nothing then it will appear with in 24 hours.. and if it dont your always welcome to message me and ill help you out as much as i can.