I have a 4.2 and under certain circumstances it does it, don't know if it relates.
I have a password set, if I turn the unit on and the password screen comes on it will automatically go off quickly if there is no input. It is not off just darkened. For quite awhile I thought it was off but not so. My switch is sensitive and at times when I shut it off it comes back on since the switch has gotten pressed twice quickly.