Testing sounds from the GNOME control Panel does not
work until you restart X (doesn't state that anywhere):
execing: bell-properties-capplet --id=9 --xid=29361396
Priority 50 : Registering Id =
sh: -c' requires an argument
The above was displayed after switching back to the virtual
console that was running x.
This bug is four months old. Please try the latest GNOME and open a
new bug if the problem still exists.