Hi guys, I know this is probably a stupid question....but hey that's not stopped me before ! ...... I have had Xbox Music Mixer since xmas and all of a sudden it has stopped working. Other games are fine. Looking at the disc there are no scratches visible at all. In fact, it's perfect. Is there anything I can use to clean the surface or does it just sound like a dodgy disc ? It was ordered online and the thought of all the hassle to get it exchanged is putting me off. Just wondered if there were any last things I could try. regards. Our karaoke parties are counting on you !