debian/unstable+KDE: screensaver/lock session not working

[Bruno.Voigt@ic3s.de]

Hi all,

I have a debian/unstable box running KDE which gets nearly daily patched.
For some months ago the screensaver and KDE kicker lock session button 
stopped working.

manual starting of xscreensaver & running xscreensaver-command -lock 
works.

How does the kdscreensaver & session lock mechanism work in detail?
How do teh different components interact?
How can I trace its execution path and check if everything is in place?
What config files are used?

Purging and reinstalling these packages didn't help:

ii  kscreensaver                                 3.5.5-1  additional 
screen savers released with KDE
ii  kscreensaver-xsavers                         3.5.5-1            KDE 
hooks for standard xscreensavers
ii  xscreensaver                                 4.24-5  Automatic 
screensaver for X
ii  xscreensaver-gl                              4.24-5  GL(Mesa) screen 
hacks for xscreensaver

TIA, Brun