Whats wrong with my XBOX 360!?

I owned gears of war 2 for a while, then i lost it. I found it about a month later, and quickly popped it in my xbox 360. It didnt work, for obvious reasons. I recently bought another gears of war 2 disc, and it still is unreadable. Then i bought a disc cleaner and it still doesnt work. My system reads all my other games, but it kinda skips on all my movies. Im thinking theres a problem with the laser reader. Has this happened to anyone else?