Mehhh! @piper I've cycled through about four attempts to follow your procedure, but no dice.
I don't know whether it's relevant, but in systemsettings > input devices > keyboard I have the US and DE layouts set, and the applicable icon automatically parks itself in the system tray.
First, I followed your procedure exactly as you wrote, but after reboot I had only a system tray with the layout icon -- the volume, device notifier, and notifications had disappeared. So with widgets unlocked, I fixed it as per your procedure, locked the widgets, and shut down and restarted X. When it came back up, the other icons were stripped out, leaving only the keyboard layout indicator. So I tried another tack -- I unlocked widgets, and deleted the system tray entirely, locked widgets, and then shut down X and restarted X. The desktop and panel came up correctly and with no system tray, as expected. I unlocked widgets, added a system tray, which immediately showed the layout icon. Then in system tray settings > extras, I added the device notifier, volume control, and notifications. I locked widgets, shut down X, and restarted X. It came up with a system tray that was blank except for the layout icon. The other thing is, even though I did not check them before restarting X, it added the updates notifier and network connection indicator and I had to uncheck them (again). So I'm saying there's a bug in there somewhere.
