This is the second time since Friday I've had this problem - my PowerBook refuses to see its battery. To fix this I have to remove the battery and then put it back in. The battery will then read at 0% and charge for a while. However, it doesn't report the charge changing. The first time, it eventually was just at 100% all of a sudden. This time, it's still supposedly at 0%. That probably has something to do with the fact that it was never unplugged last time and has been running on battery for some time this time. I was running the PowerBook on battery when I noticed that it reported no battery this time, so the battery isn't actually dead. Last time it happened after playing Call of Duty. This time, I unplugged my Bluetooth Adapter, iPod, and power cable then took it to another room. It had woken up, but the lid was closed, so it went back to sleep. When I woke it up, I noticed that it was reporting no battery. The time remaining to charge will always remain "Calculating." I hadn't installed anything except Call of Duty before the problem started (I installed the Security Update afterwards). Does anyone have any ideas what could be going on? My PowerBook is outside AppleCare time (about 1.25 years since I got it).