I'd say call customer service, but they just might suggest a new battery too, plus you probably are going to have to send it in and wait 6 weeks which is a hassel. I've had some problems with electronics randomly turning off, but nothing with a cell phone. There might be something wrong with the battery meter of the phone, you could try backing up all your data, then letting the phone completly die, (just keep turning it back on by until it wont turn back on anymore), then wait a while until your phone completly resets itself (loses all data) and then recharge the battery all the way without using it and see if that makes any difference, but first I'd call customer service because they know the phone and maybe they've had problems with that phone like this before.
My 10-month-old VX6000 powers off at random times, even when it's just sitting in my pocket and I'm not using it. When I hold down the power button to try to turn it back on, it stays turned off. I need to physically remove the battery and put it back to get the power button to work and the phone to turn back on. When the phone is back on, it always has plenty of battery life, so the phone isn't just turning off due to a low battery.
Has anyone else experienced this? Any ideas for fixing it that don't involve just getting a new battery?