Kolab resource problem with KDE Kontact

[Robert Szentmihalyi]

Hi,

I am using Vontact 1.2 (which ships with KDE Version 3.5.2) on several PCs.
Now, two users have problems accessing the shared (calendar and contacts)
resources.
The resources are configured and visible in KDE Control Center, but when
exiting Kontact, a message appears saying like: "Error while saving:
Resource Kolab-Server cannot be accessed" (translated from German).
The accounts were configured using kolabwizard, and everything used to
work fine. I actually can't tell what might have caused the problem.

Any ideas?

TIA,
 Robert