Regardless of charge level, when the screen times out and goes into standby it will not wake up when I press the power button. I have to do one of 2 things to wake it up. 1. Manually reboot the phone. 2. Connect to a power source. When connected to power it will go into standby and wake up using the power button. Unplug it from power and once it goes into standby it wont wake up. I have gone so far as perform a factory reset and even after that I still have the same issue. Suggestions?