Are you sure the disk is spinning all during the game? It's normal for it to spin up when you launch, it does a disk check to validate that the disk is in the drive. After that though, it shouldn't be spinning your disk.
the same, mine spins for about a minute or so and then stops.
like Rookk53 said i think its some new disk checking thing, i have my 360 using my PC 's Internet connection since their both setting next to each other and i was checking and as long as the disk is spinning its using bandwidth then stops using it the same
time the disk stops spinning.