Gnome Apps missing in KDE system tray

killall -9 plasma-desktop
rm -rf $(kde4-config --localprefix)/cache-*/plasm*
rm -rf $(kde4-config --localprefix)/share/config/plasm*
rm -rf $(kde4-config --localprefix)/share/apps/plasma
plasma-desktop &

via forum.kde.org

Removing cache and configuration files for plasma fixed the problem. Pity that one has to remove it...