I don’t have this problem with my sandbox PC and KDE4, nor with my laptop PC with KDE4 , nor with my wife’s PC with KDE4.
What have you done to try to investigate it ?
Did you go to kmenu > Configure Desktop > multimedia > Backend and try a different backend? I have xine selected. What do you have selected. I also note my xine (via the xine-ui control) has alsa selected and not pulse.
Also, under kmenu > Configure Desktop > multimedia > device preference > audio output, one can select the order in “output device preference for the Notifications category”. … Is there anything you can tune there?
Take a screen print of your settings BEFORE you change anything, so you can restore it afterward if it does not work.
I just had a look oldcpu, and I have ONLY xine in there, nothing else.
It reports version 0.2.60, and zypper reports version 220.127.116.11-2.pm.6.11.
The notifications option (I guess that means system sounds) has either HDA Nvidia Conexant analog, or Pulseaudio as options, but selecting pulse gives an error about it not working and switching back to Conexant analog.
The .ogg system sounds play perfectly, as does the test function, it’s only .wav files that give me grief.
Under Backend, I have no idea what Deinterlacing method does, should I try messing with that? It has only DVD checked and use_vo_driver selected.