Just to add $.02 to this discussion...
The Seagate Freeagent drive sleep-mode is a well known problem.
Basically, it is my understanding that the power-down mode on the FreeAgent series is not compatible with the way that Linux tries to re-awaken a drive from a sleep mode. Yes, Linux. I've run into this exact same problem on Linux boxes (Ubuntu) using the same 250GB Freeagent drive that I used to use on my 722. Works fine when awake, but once it goes into sleep mode, Linux can't re-awaken it. I am almost positive that I've read somewhere that the underlying code in the 622/722 is Linux-based. If so, I'd bet that it's the same bug.
Disabling the sleep mode with the Freeagent software works, but then your drive will stay hot (literally!) and spinning forever. Not great for power consumption nor longevity of the drive due to the heat and constant spinning.
On a PC, there is a way to patch the Linux OS modules that handle the USB communication. It took me, a Linux noob, about 20 minutes to research, apply the changes, and correct the problem. It involved modifying a handful of configuration files. For someone that knows what they're doing with Linux, it might take 2 minutes.
If this is the same problem, I'd think that DishNetwork could have this fixed with a minimal amount of coding effort on their programmers' part.
Doesn't matter to me anymore, as I've replaced the Freeagent 250GB with a Western Digital MyBook 500GB. The 722 has no problem waking up this drive from its sleep mode.