So my buddy and I both own copies of Fifa 11, I had mine before he recently got his. Mine never gave me any problems and I know fairly well how my disc looks. We used to play my fifa, but I came back one day and put what I thought was my game in, but it wouldn't even load. I took a close look at the disc and recognized it wasn't mine, but wanting no conflict because I had no proof, I let the matter go and we began using his copy. However today, I noticed that on his game manual, a spot of paper was missing on the front cover, and the same spot of paper was stuck to the defective game, implying that the defective game was his just as i had suspected. I checked the other fifa copy and recognized it to be mine (it has a distinct set of cracks around the middle circle). I plan on switching the copies back and having mine, but i know this will lead to a lot of problems. Is there any way, like serial numbers or whatnot that can help me prove my fifa copy? If there is no way then I will go ahead and switch them. HELP PLEASE AND THANKS IN ADVANCE.