javaws not working with KDE

I used to have problems with KDE 3.x audio system conflicting with other services, and the solution was always to turn off all KDE sound. With KDE 4 series I didn't have this problem, and I could use the facilities of the window manager. Until now, when I decided to watch the recorded phyloseminars (from home, since my Mac at the lab runs smooth). These video-conferences are based on the EVO software (launched via Java Web Start). It was clear that java was having a hard time accessing my audio devices: the seminars had no sound and EVO's FAQ mentioned competing applications. The solution I found (or a version of it) consists in installing the PulseAudio sound server and removing conflicting programs:

1. Install PulseAudio and the GUI control panel: aptitude install pulseaudio pavucontrol
2. Include this line in ~/.xsession (or ~/.xinitrc): pulseaudio --daemonize
3. Restart X system and check if pulseaudio is accessing the sound device: lsof | grep /dev/snd

In my case I realized that there was another program, called knotify4, competing with pulseaudio for the device. This is the notification system of KDE (with fancy bells and whistles), and to turn it off I went to System Settings -> Notifications -> System Notifications -> Player Settings and selected "No audio output" (the configuration file is ~/.kde/share/config/knotifyrc).

In hindsight, I think that simply disabling the KDE sound notifications would have been enough - and I was explicitly advised to shut down pulseaudio - but I'll keep this information as a logbook... The drawback so far is that there is still conflict when some programs try to access the output sound, like flash (youtube...).

Now at least I think I'm ready for the next lecture.