Interesting that you run OnyX every week and your Mac apparently developed symptoms between one run and the next that took two runs to clear up. (Do you restart after running OnyX?) Let's see what happens down the road.
Y'know, your sig just rang a bell in my head, and, since you don't use it, I'm wondering how you're maintaining the battery in your iBook G4?
Edit: You'll find Apple's long-term battery storage advice
here.
