TDE Sound System / Notifications - not working

Hi All, As I've done numerous times in the past, I've built & installed TDE from source (git) but this time, system notifications don't work for me when attempting to use the 'TDE sound system'. Sound works. I can play sound files from the command line and if I select an external player, say gst123, in the 'System Notifications' configuration dialogue box I can hear the configured notification sounds. But if I use the default setting of 'Use the TDE sound system' I hear nothing. Additionally, if I set the notification to 'Display a messagebox' or 'Log to file' or 'Print to standard error output' I get nothing from there either. Going to Settings -> Sound & Multimedia -> Sound System and playing there makes no difference. 'Test sound' does not produce any output, toggling Enable makes no difference, selecting Autodetect or Alsa makes no difference. 'artsd' is running and does get restarted if and when settings are changed. Anybody experienced anything similar? Mike. -- Any question is easy if you know the answer!