Version: 2.0.x (using KDE 4.4.4)
Dragon should disable the KDE screensaver while playing. This is especially true when playing in full screen mode.
The "org.freedesktop.ScreenSaver.Inhibit" DBus interface looks promising.
Reproducible: Didn't try
OS: Linux (x86_64) release 2.6.34-gentoo-r1
It just occurred to me, that it may not be the screen saver that is firing for me. My usual screen saver doesn't come up, the screen blanks. So perhaps it is more accurate to say that monitor power saving should be disabled as well.
*** This bug has been marked as a duplicate of bug 243035 ***