UPDATE: Apparently if you eject the tray with the disc & re-close it, it will stop making the disc spin.
A VIDEO DESCRIBING THE ISSUE POSTED BELOW:
This is an error I have been experiencing with Gears of War 3 purchased on Games on Demand (being played off the hard drive with no disc required). The issue is that if there is another disc in the tray, it will start spinning as if Gears of War 3 is trying to read the disc.
This is the only "GoD" title I own that has this issue, others work without a problem.
I deleted the cache on the hard drive, which worked once. But once I turned off the Xbox, and played the game later on, the issue came back!
I was wondering if other people have been experiencing this issue, and whether or not someone might see this and forward it to the Xbox Live Marketplace crew for a possible patch.