I've seen so many posts on this topic that I can see the eyes rolling, but I am really perplexed, and I'd appreciate your patience.
For some time now, and I think the problem started when I upgraded from 9.0.4 to 9.1, when Energy Saver is set to sleep after 10 minutes idle and, although the drive is spun down and the screen is blacked, there is no deep-sleep pulse, which means that something is active, right?
Anyway, I've tried all of the normal fixes and found that the only thing that works is to trash all of my Preferences (save those in folders, mainly third-party info that would be lost, and painful to re-build) and restart. Then all is well and works as expected...for a while. Eventually, I lose the pulse sleep and I must repeat the trashing of the Preferences.
With 9.2.1, I seem to be free of the issue. Occasionally the Energy Prefs are corrupted and they must be trashed, after which all is well. I've not yet had to resort to the remedy explained above. But, it is a bit slower, and I understand that it is primarily meant to be used in OS X Classic. So, I'd really prefer to go back to 9.1.
But, I am tired of waking in the morning to find that damned solid green light after letting the machine put itself to sleep and I want to know how I can fix this.
It must be software-related, as I am using in all three OS the same Energy Saver Control Panel (3.0.5, which came with 9.2.1 upgrade) that works with 9.2.1, but not with the others.
Finally, is it so tragic that I don't get that pulse sleep? How much harder is it on the iMac to be left in that limbo state for so long?
Thanks for the help. And, again, I am sorry for bringing it up again.