After playing a video with dragon, the settings on my monitor have always gotten reset. Even though I have the monitor set to never sleep, it will always turn off after a couple of minutes after playing a video.
Which version of the KDE SC? And which distribution?
Also FWIW, to me that sounds like a bug in the power management components.... what happens is that dragon inhibits screensaver and screen deactivation when playing a video, it then releases the inhibition upon stopping the video. naturally it would appear possible that solid (the power management library) does not store the previous state correct so stopping the inhibition in fact becomes activating the mentioned feature rather than restoring whatever state it was in before the inhibition.
Oh, also how do you turn off screen power management?
kde 4.9.2, on kubuntu 12.10, x64.
I go into system settings, power management, then check the screen energy saving box (it stays unchecked even though screen still turns off), hit apply, uncheck, hit apply.
Sounds like a powerdevil issue then.
*** This bug has been marked as a duplicate of bug 295164 ***