Missing Halo 3 achievements?

[I love Amber]

I've beaten Halo 3 on normal and heroic but I haven't gotten credit on my gamer score, even though my xbox says that the levels are complete. Does anyone know how I can get my score? (I've already gone back and replayed the levels.)

 

[x-dude]

hhha are u tryin to make panic cuz this happened to ps3 too ..just wait until it fixes (always if its true cuz this didnt happened to me ) anyway microsoft will fix it

 

[joey]

there is a logical answer to this that i cant remember, just make sure you replayed the first level (its just a video) and make sure you have credit on you beating it buy just making sure it sais you beat it on what ever level