nexus 7 turns on and stays on while not in use.

[sleepy548]

So I press the power button to put the nexus 7 to sleep. When I open the cover it is sometimes back on the google lock screen. The lock Screen stays on until I hit the power button again to put it back to sleep. It's drained my battery several times. What can I do to stop it from doing it again?

 

[revjong]

I have also had this happen twice since the latest update. Never before.