etch: KDE screensaver not working

[Bruno Voigt <bruno@voigt.tv>]

Hi,

on my debian/etch system with KDE - which I continiously aptitiude
(dist-)upgrade every few days since pre-sarge,
I have the problem that the screensaver does not kick-in. automatically.

Via the KDE control center it is enabled (empty screen) and set to start
after twenty minutes and lock after 120 seconds.

How may I find out why it doesn't work on this system? What config files
should I check?
On similar other systems of mine it works as expected.

TIA for any hints,
Bruno

dpkg -l | grep screen
ii  electricsheep                        
2.6.6-1                              screensaver showing collective
dream of sleeping computers
ii  kscreensaver                         
3.5.3-1                              additional screen savers released
with KDE
ii  kscreensaver-xsavers                 
3.5.3-1                              KDE hooks for standard xscreensavers
ii  libxss-dev                           
1.0.1-4                              X11 Screen Saver extension library
(development headers)
ii  libxss1                              
1.0.1-4                              X11 Screen Saver extension library
ii  x11proto-scrnsaver-dev               
1.1.0.0-1                            X11 Screen Saver extension wire
protocol
ii  xscreensaver                         
4.24-4                               Automatic screensaver for X
ii  xscreensaver-gl                      
4.24-4                               GL(Mesa) screen hacks for xscreensaver