So i have a 1st gen black macbook that i upgraded myself to 2 gb RAM and a 120 gb HD, i got it back in July, and it's been great until recently, where it will either shutdown if your unplug it from AC power, or won't start up unless it's running on AC power. The battery lights say that it's either mostly or fully charged, the computer recognizes the battery and says the percentage and how much time till fully charged or whatever, and the AC power thing has an orange or green light, so everything seems like it's working fine, but when it comes time to run on battery power, it works while it calculates the time left on the battery, and then it shuts down immediately. Understandably, this is quite annoying, since it's a laptop and i can't always be tethered to a power cord. I don't think this is the dreaded random shutdown, because it's not random, it only happens when the AC power isn't present. I tried resetting the PMU to no avail. It happens maybe 75% of the time, and luckily for me, that 25% is when i try to get people to witness this. Any ideas???