Why does my encrypted tablet randomly ask for password?

Why does the password screen come on while I am using it? If I change tablet position the pswrd screen comes on...if I flip a page in an emag it comes on...it has even come on while reading a pdf and flipped a page? Annoying at times.

from Android Forums at AndroidCentral.com - Ask a Question http://ift.tt/2ajTdNT
via IFTTT