How to get rid if the screen turn to blank when watch movie or etc after 10 minute. Well, I checked that it consider a bug when look at launchpad. But, there is a way to work around by add below line to Xorg.conf,
Section “ServerFlags”
Option “blank time” “0″
Option “standby time” “0″
Option “suspend time” “0″
Option “off time” “0″
Option “screen blank” “0″
EndSection
Try again after restart your system.