Indeed. I recently put my 501 in my bedroom, and it's driving me crazy. The disk is usually spinning, even when the receiver is off, at all times of the day and night. But also (once/hour?) the receiver spins it down. I think Dish is trying to kill the drive.
I ran into this phenomenon and for me it has an interesting cause.
As you know, when the drive is idle for a period of time, like an hour, it goes to sleep and spins itself down.
The problem is that the drive notifies the operating system that the drive went to sleep.
The operating system, which I think in the DiSH Players is Linux, responds usually by doing something that requires it to write to the disk. Lots of unpredictable system calls in Linux require the disk to spin up which is ironic.
Then the disk spins up. Funny it's usually doing this only to respond to the sleep signal.
Then it spins for about an hour (or whatever the sleep timeout period happens to be).
Then it goes to sleep and it sends the "I'm sleeping" signal.
Drive wakes up...
...this process repeats forever...
On several idle servers I've taken the drive and checked the "SMART" statistics. The drive spin-up/spin-down rate is about the same as the sleep timeout that you set.
Windows does this often, too.