Comment 15 for bug 410466

Same to me. I use kubuntu 9.10 AMD64 on a Dell Studio. It was an upgrade-installation from 9.04.
I've got two users: user1 has the problem as described above, user2 not (both existed also before upgrade from 9.04)
As I played around a bit, I recognized that even some other system-notifications - as unplug the ac-adapter - just show the notify-popup but play no sound. Also no login-sound is being played anymore.

Just for testing I configured to use /usr/bin/mplayer instead of "KDE Sound System" under "System Settings" -> "Notifications" -> "System Notifications" -> "Player Settings". After that user1 can log out, login-sound is playing and all the other sounds well.

BTW: I wanted to test if switching off the logout-sound fixes the problem, but I cannot find any entry named like "KDE System Notifications" in the drop-down-list "Event Source" of "System Settings" -> "Notifications" -> "System Notifications" -> "Applications"
;-( Where has it gone???