Version: (using KDE 4.1.3) Installed from: Gentoo Packages In System Settings Display Power Control when DPMS enabled in xorg.conf option "Enable display power management" is off. But if option "Enable display power management" is on with setting timers to 0, then, by fact, DMPS is disabled. Thereupon, I offer rename option from "Enable display power management" to "Override Xorg DMPS settings" that it will be more logical.
Note, that in Russian translation this says "Enable display power saving", which should obviously be "Enable display power saving management", since if disabled, power management is controlled by Xorg DPMS.
The Energy KCM has been outdated and unmaintained since some time ago. In the other hand, KDE4 gained a new (and powerful) power management daemon: "PowerDevil" (which is accessible from System Settings/Advanced/Power Management) Today we removed the Energy KCM from the code in KDE 4.4 development trunk, to avoid some conflicts between the settings of the two modules and to set PowerDevil as the default power manager (it was the default one already). To the people using KDE4: disable the Energy KCM settings and configure your power management options using the new PowerDevil. If you encounter the same problems, please file new bug reports against the "solid/powerdevil-daemon" product on bugs.kde.org Thank you.