I have a Mac Pro with 4 internal hard drives, 2 external hard drives, the built-in SuperDrive, and a new Pioneer BDR-205 internal Blu-ray drive. Here's the problem: If the "Put the hard disk(s) to sleep when possible" option is enabled, when the system puts the BDR-205 to sleep, it will never wake up unless the computer is shut down and restarted. (Basically, it disappears from the System Profiler and can no longer be accessed.)
If I turn off the Energy Saver "Put the hard disk(s) to sleep when possible" option, then the BDR-205 never has a problem -- but then none of my other drives ever go to sleep, either.
Does anyone know of a way to exempt a specific drive (or drives) from being put to sleep by the "Put the hard disk(s) to sleep when possible" feature? I've found where the settings for this feature are stored, in \Library\Preferences\SystemConfiguration\com.apple.PowerManagement.plist (the setting is Disk Sleep Timer -- 0 = never sleep, any other number = how many minutes before a drive is put to sleep), but I can't find where there might be some undocumented option to allow us to say, "Don't put THIS drive to sleep". It seems silly that this option is an all-or-nothing proposition.