KDE: Systemtray sometimes disappears after some time

When KDE's Kicker reloads, it undocks all system tray icons, but apparently all KDE applications redock themselves. GTK applications system tray icons seem to create an extra loose window with the icon, and plain Qt application systray icons seem to disappear entirely. Although it doesn't really seem to be a bug in Qt, it would certainly be nice if Qt applications redocked themselves.