halo 3 save problem after beating the game?

[gnapoli1985]

I have beaten the game on normal, but some how the game will not save when i beat the tsvaro highway level <which i have beaten about 6 times since i discovered it wasn't giving it to me>, so it says i technically didn't beat the game. i was wondering if any one else has had this problem, and if they have been able to fix it. it is incredibly annoying.
thank you very much
-g

 

[Danyaal R]

I think your disk is scratched. You should send it to microsoft and have them replace it.