Had it for 18 hours, first unresponsive 9930

Barely 18 hours, not even, I got the red light blinking as if I have a new e-mail and non of the buttons will respond, screen is pitch black (completely off). I do not have anything that should cause this behavior and the last thing I did was delete a few e-mails and move some around and then put the phone down on my desk.

Now, it kept on blinking until I rebooted it via keyboard. Thank god that boot times increased substantially, but any ideas what may have caused this? I have over 175MB free space for app and 5.70GB for storage (not sure why it is reporting 6GB capacity).

I also noticed ghosting after I close an e-mail, it won't completely fade away, you will see a tiny bit of the e-mail extremely transparent at the center of the screen, until you hit Back or End again. Not a screen/hardware problem, but software not completely fading/closing the e-mail away.
Running 7.1 Bundle 457 (7.1.0.163, Platform 5.1.0.137)