I'm currently running Ubuntu 13.10 on my Dell XPS 8700. I've got two monitors hooked up to the computer: one via DVI and the other via DisplayPort. The two-monitor setup works perfectly for the most part, but I've got one annoying problem: when the systems is inactive, only one of the monitors turns off.
Under All Settings ⇒ Brightness & Lock I have it set to turn the screen of when inactive for 5 minutes. The one that turns off is the one connected with DVI. Any ideas?