It seems that my assumption that the staff group had anything to do with it was wrong. I've encountered the problem again while not being a member of staff.
I've tried logging out and in several times without changing anything (while being a member of staff this time) and approximately half the times desktop effects are working. Restarting kdm seems to guarantee that it works. The test that I did to verify that the staff group was the cause seems to have been a coincident. _________________________________________________________________ Express yourself instantly with MSN Messenger! Download today it's FREE! http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/