Thank you for the replies.
This begs the question then, why doesn't the same phenomenon occur when I shut down from Windows XP? Since the only difference is the OS, I can only imagine that it must have something to do with the power management settings. (Perhaps my topic should have read "power supplied to keyboard" rather than "power supplied to motherboard".)
I know it's not a major issue, but it is baffling, especially considering other threads I've read indicated that by selecting that check box I mentioned (for various pieces of hardware, but most people seem to think the main culprit is the firewire port), the issue has been resolved for others.
I guess it's really more of a mental problem than a computer problem, then.
Guess I'll just have to stop worrying and love the bo... I mean, NumLock light.
. o O (Thanks again.)