Put display not to sleep

[Ubuntu User]

Hello,

While I am watching a film with Totem Movie Player, my display is put to
sleep. I don't understand because the following options are off:

- Power Management Preferences
	Display->Put display to sleep when inactive for: NEVER
- Sessions
	Power Manager: Dis-enable.

I think, it can happen because of I installed compiz (advanced desktop
settings). Am I wrong?

What can I do to watch a film and the display won't be put to sleep?

Thanks

--
Ubuntu User <redacted at example.com>