[danoxen]

Did you ever figure out what caused this problem?

Same thing seems to happen to mine about once a week. I take it out of my pocket or off the desk after not using it for a couple of hours and it won't power on. Black screen. I do a soft reset and it turns on fine, battery power is at 60% or higher.

The first time I thought it was because I had left the Wifi on and the battery had overheated and it had turned itself off. This time though nothing was running that would cause it to overheat. It was in my pocket and didn't feel warm.

I guess it could be frozen with the screen off? I'm running the stock Sprint ROM that I hard reset the day I got it. I've added the standard tweaks listed on the stickied post here and installed quite a few standard programs. None of them were running when this problem occured though, and they are all installed on the device, not the card.

Annoying since I will be missing calls and messages without even knowing its dead in my pocket....