Over the course of just a few weeks, battery time on my G4 TiBook 550 went from 4+ hours (with the screen brightness turned all the way down) to less than an hour, real time. I did a reinstall to ensure I didn't have a runaway (M$) process hiding in the background, but got the same results. I know it's possible for a battery to "wear out" after three years or so, but over the course of weeks??