missing achivement it shows i unlocked them legit

I can't remember if I was connected to LIVE at the time of the achivement unlocking, the only reason I wouldn't have been is if my home internet dropped momentarily, or my phone went out of a 3G zone. The Xbox games show the achivements as unlocked on the
console, and the WP7 games show as unlocked on the phone, but they're missing when I go to xbox.com and look at my profile.

Make sure you read how to unlock achivements before playing the game, you most likly miss something during your campagin mission or maybe you unlocked already and dont know it. just move on to the next achivement if that one don't unlock i strongly requiremend
you read how to unlock them or maybe it just ghiltch out or something, im really not to sure. try waiting for others to respond to this post if my response isnt helping.

@Miss ErmineYes - it seems that DLC achivements are taken out from server. But this bug is well known.

So look at my profile - it shows that I have 29 unlocked - but on my own xbox I have over 30 unlocked because there are only 2 from dlc that I didnt do till now

same on forza 4 i should have 510G but i curently showing 325G achivements that i had already unlocked but re-unlocked yesterday

well my achivements I got back legit this time and its messed up cause im not supposed to get them back so idk what u talking bout u sealed them away cause u didn't and I got gs for your mistake cause u never actually locked the 0 Gamerscore game achivements
and I got it back legit so I don't want to get banned by ur guys mistakes