Did the OTA update today. All seemed fine (except for the very annoying issue with the unlock screen). But on a phone call this evening, When I took the phone away from my face, I saw it was on the lock screen (which shouldn't ever appear in a phone call). The call was still active, but the screen and buttons were completely unresponsive. Couldn't go past the unlock screen, the little green phone icon was still in the notifications bar. Green phone stayed there after call disconnected (other party hung up). Indicating nonresponsiveness of the UI (not just to my commands, but not responsive at all). Eventually, had to pull the battery.