I've noticed that when idle, my G4 iBook's hard drive makes a regular ticking sound. Kinda like a "tick-tock....tick-tock....tick-tock" I tried to open activity monitor to see if there was any service that could be doing something but I can't find one. Has anybody else experienced this? I don't care if it makes the noise, I just wanna know why it does it. At least its not as annoying as the constant grinding coming from the hard drive on my DVR. Now THAT gets on my nerves.