Comment # 18 on bug 913339 from Wolfgang Bauer

(In reply to Stakanov Schufter from comment #17)
> I am so sorry, but after a complete shutdown and a restart the system tray
> icon is gone as before, patch or not. Sorry for giving you false hope.

Which one, the NetworkManager?

Again, this is a system tray applet, and completely unrelated to support for
legacy system tray *application icons* missing.
So it's also unrelated to and not fixed by xembed-sni-proxy.

KDE dropped support for legacy system tray application icons, xembed-sni-proxy
adds it back.

Applets randomly not being displayed is an unrelated problem, it is known and
being investigated, see comment#14.