My phone has been messing up for awhile.. The screen will go black, but my phone is still on, and the notification lights will still be flashing. I can't get it to turn back on even after pushing the power button, therefore I have to take the battery out. My phone will also randomly turn completely off. It has also been telling me that my SD can't be detected, and that it'll have to be restarted so that it can try to be detected. And for the first time this evening, it did it to me twice in a row. Does anyone have suggestions? Tech support in store hasn't been any help at all.