360 Achievements Question

[cokecan]

Hey guys, I recovered one of my friends gamertags on my 360 a few days ago so we could take the 360 up to another friends house (not connected to the net here) to play some guitar hero

My gamertag and my friends both signed in ok on the guitars and we spent all night playin co-op and face off etc. We unlocked a few achievements like 8x multi in co-op, 200k pair etc and they showed on both our gamertags

Since then my friend has recovered his gamertag on his 360 but the achievements we unlocked have dissapeared??? Mine are still there on my gamertag though

As far as i'm aware the achievements are tied to your gamertag and not the saved game file or the console etc???

Any idea's whats going off?

 

[cokecan]

I tried to login with his gamertag last night after he'd recovered it on his 360 but it moaned about xbox Live details being incorrect or somethin (didnt really pay much attention)

I'll have another go tonight though. Recovering his profile again wont do any good because it will just be the old version he's allready recovered on his