Can some1 help answer this question about my xbox 360?

Okay so i bought my elite 120g about 3months ago and i havent had any problems playing the games i got with it m effect 1,2 halo 3 and odst, oblivion, asins creed 1,2 etc. well i purchased fable 2 and it didnt work so i went and got a new one and it wont read it either mind you the game is freshly opened. now i dont know but it seems that it doesnt like fable im really stumped and i dont have the ring around any disc to indicate that it was moved and scratched it it just doesnt want to play fable 2 and the chances of getting 2 brand new games that dont work at all with bad codex or whatever it uses to read it is very slim and i played it recently on my buddies xbox so can anyone give me some ideas im already considering sending it to Microsoft to be looked at but i dont see no reason to send it in if its just some little cache that needs to be cleaned or whatever ooo and it loads and says play game and then once it loads it says disc is unrecognized