I have Ubuntu Studio 12.10. I don't want to switch off my monitor ever. My 27" monitor is of new generation, it has a sensor to go to sleep mode whenever the user is not sitting in front of it. I can easily turn off the sensor if I want to watch movie from the distance.

In Power Manager I have the following settings:
On AC [Actions] Put the computer to sleep when inactive for: Never
On AC [Monitor] Put display to sleep when computer...: Never
Switch off display when computer is inactive for: Never

In Screensaver Preferences:
[Display Modes] Disable Screen Saver
[Advanced] All disabled

However, when computer is inactive for some 10 minutes the display switches off, and I must move a mouse to switch it on.
Is there something I missed?