Version: 0.9 (using KDE 4.4.2) OS: Linux Installed from: Ubuntu Packages nm-applet has an option to disable and enable networking. However, if you disable it in nm-applet and switch to knetworkmanager, knetworkmanager will just display a message that networking is disabled, and provide no way to enable it. There doesn't seem to be an option for this in systemsettings, either. I somehow ended up with networking disabled, and it took me a while to figure out how to get it back.
Sorry, just realized there was already a bug for this. *** This bug has been marked as a duplicate of bug 232531 ***