I lost email sound notification in Kmail Mandriva 2008
 

I'm using a 2008 32-bit Mandriva.
It worked great for a while and suddenly I lost the Kmail sound notification, for new emails. My sound was /usr/share/sounds/KDE_Notify.wav
nice sound of a crystal. I don't hear it anymore, only sometimes I can hear a tiny fragment of it. The other sound programs work fine - Kaffeine, Amarok and others.
I don't even know where to start troubleshooting.
help! I've got silent mail..