I have a 12" Powerbook G4 that is about 4 months old. When I plug it into AC power the cable LED turns orange as if it is charging. When the battery icon reads 60% the cable LED turns green as if it is fully charged. If I unplug the power chord the battery runs down as usual. At around 25% it just crashes, it doesn't sleep; it just flicks off. I have repeated this many times with the exact same result. I have followed the instructions for recalibrating the battery and for resetting the PMU and neither has helped. Any help would be much appreciated.

Being that it is still under warranty, try taking it to a local apple store's genius bar. Most likely they will copy your files over to a new one and hand you the new laptop no questions asked (that's how it was for me). Seeing as it is still under warranty I wouldn't suggest taking anything apart as that would void the warranty.

If you have reset the PMU and recalibrated the battery I would suspect something physically is wrong with the computer. You should be able to locate an Apple Authorized Repair Center near where you live to have it serviced. Managing one of those centers myself the 12" PowerBook are the hardest machine to repair because of how tightly packed everything is inside. I would suspect either the DC-in board but probably the logic board. You might also want to call 1-800-275-2273 (APL-CARE) to see what their people can do to help you. Good luck!