My US Celluluar Samsung Galaxy S Mesmerize will not power up unless it is plugged in with the charging cable. When I try to power up on the battery, the battery symbol appears when I hold down the power button. The battery symbol shows all grey like there is no charge even if battery is charged. If I plug phone in with USB cable, either into wall charger or computer, the battery symbol appears showing the proper level of charge and the phone powers on and works properly. When the phone is not plugged in, it apparently does not recognize that the battery is charged. I have tried this with two different batteries with the same results. This started happening a few days after I took the phone in for the latest software update. Would re-setting phone to factory settings solve this? Thanks.