I recall I had a heck of a time in the past with the older kde, in 
keeping the monitors/screensaver set so it might show a few minutes of 
the screensaver of choice, and to powerdown the monitor after a few 
minutes of screen saver.  But it can't remember those settings more than 
a week or so, so I just put a couple entries in my crontab:

*/1 * * * * * xset +dpms
*/1 * * * * * xset dpms 300 0 600

To see if refreshing its memory hourly will effect a fix.

But it sure would be nice if we didn't have to overpower it like that to 
keep it working.

In TDE control center, its set 5,0,10 but that seems not to affect it, 
when it has failed the pheripherals/display/screensaver and display 
power management are all zeroed out or the checkboxes cleared.
It appears is as if a zmalloc has gone astray?
Under appearance/screensaver its set to start a slide show after 4 
minutes.  The memory of whatever it uses for the "elevator music for the 
eyeball" also seems transient, it switches to either a blank screen or 
some glx thing that burns up the cpu, again at random intervals that do 
not seem to correlate with the dpms settings failures.

Info, bug action, your pick. ;-)

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>