I've got a 2g unlocked. Nothing installed but the sinful MMS package (but it did this before I installed it anyways). Maybe once or twice every week or two the battery will drain rather quickly during the day. It'll last from 8am - 6pm off a full nights charge. So once it dies, I'll try to turn it back on but it remains dead. As soon as i plug it in, it turns on as usual but then reads 50% battery. The remaining "50%" then takes about an hour to drain to zero again. The battery has been calibrated and most days it works perfectly fine (2-3 days per charge) I think I've noticed that this happens on a day where I might use the phone a little more than average, but definitely not enough to make this drastic change. Any ideas?