new to the forum...for a few months now, my powerbook has been having some odd power issues. It won't see the battery at all anymore, and can only run off the AC power....tried replacing w/ new battery...same issue...won't see it, won't charge it, and won't run off of it. Also, since upgrading to a new OS version, the laptop has started falling asleep while I'm using the computer constantly....goes through fits of falling asleep every 15-30 seconds or so while in use. Anyone hear of anything like this before? Power Management Unit issue?