Xbox says "Disc Unreadable"....?

Hello, let me just cut to the chase, my xbox is giving me the "Disc Unreadable" message, when the disc is perfectly fine, in fact i got the game last week all my other xbox games and DVD's are working but not Gears of War 2, it can't be the disc because it's in perfect condition and this is pissing me off to court-manuevering options. So if it's not the disc what is it? if it's something to do with the hardware, if it is, then i can't open it because i'm worried i'll break something.