No network connection after logout from KDE

11.2RC1 and M8, probably older versions as well.

How to create a system network connection using NetworkManager?

I use NetworkManager which starts automatically and connects to configured wireless network (automatic KDE login). It works just fine, but when logged off (e.g. for console session), knetworkmanager is shut down, of course, and there’s no network connection anymore. System connection checkbox is disabled.](

X session for root also displays disabled mentioned checkbox for knetworkmanager.

I would expect to have a network connection regardless of my X session.

Any suggestions? I would like to avoid ifup, as I use my laptop on many different wireless and wired networks.