Happened on 20120614
1. Mobile data/3G on
2. Snapped a picture.
3. Received/sent some messages on WhatsApp
4. Put phone back into pocket.
5. Went up the elevator.
6. Took phone out of pocket and saw the boot screen!
7. Copied /proc/k_lastmsg as backup
Could this be caused by the Titanium Backup restore of Angry Birds data? Maybe, but... 1st June 2012, took out the phone from pocket only to find it dead. Couldn't get screen to wake up via power/home buttons. Had to long press power button to startup. Didn't even have Titanium Backup installed back then.