Dang, this happened once before but I can't remember how I fixed it.
The battery indicator on my TiBook550 shows the battery with an X through it. SlimBatteryMonitor (what I normally use) won't show up at all. My PowerBook doesn't think it has a battery.
Normally I run plugged in, but I did unplug boot it up under battery power just to be sure that the battery was actually working. No problems, but no indicator either.
Anyone know why this happens, and a fix?