Dj YB wrote:
correction, this problem is only in cairo-dock tray when I use the plasma tray there is no problem.
The keyboard layout indicator now uses the new KStatusNotifierItem class instead of the old KSystemTrayIcon. This implements a new, more modern systray protocol. It can fall back to the old one when run under a non-KDE desktop, but you're running a non-KDE systray under KDE, which isn't really supported.
Try disabling the status notifier watcher kded4 service under System Settings / Advanced / Service management, that should make KStatusNotifierItem fallback to the legacy systray protocol which is supported by cairo-dock.
Kevin Kofler