Sometimes only 1 desktop and no window border in KDE

[Anton Liaukevich <anthonyl@uvaga.by>]

I have been using Lenny for several weeks yet (with KDE 3.5).

For first two week all was Ok but then such a bug appeared:
1) In the KDE panel only one desktop available (but I have 4 desktops).
2) All windows I open have no border!

This bug appeared after I (or another user of my computer) log on first 
time (after OS boot). If I log out and log on once again KDE begins to 
work normally.

My software (Debian Lenny uptodate)
     kernel: Linux 2.6.25-2-686
     video drivers: legacy Nvidia commercial driver installed from 
NVIDIA-Linux-x86-96.43.05-pkg1.run
     x11: xserver-xorg 1:7.3+14
     kde: kde-core 5:48
     logon manager: kdm 4:3.5.9.dfsg.1-2+b1
     panel: kicker 4:3.5.9.dfsg.1-2+b

I only use kdm (don't login at console).

P.S. There are 3 real users of my system and often we use switch user 
feature. Perhaps this influence on this situation.