System event sounds gone missing - again...

[O. Sinclair]

Running Kubuntu 7.04 I yesterday made a rather large upgrade, 80 mb or 
so of everything from kernel image to small apps.

And once again (not first time, happened with 6.06 too) I have no system 
event sounds. Can play music, movies etc with sound but no sounds for 
like mail arriving or whatever KDE related.

anyone with the same problem and/or ideas of where I can look for the 
cause of the problem and possibly rectify it?

Sinclair