Do you prefer to use the old NetworkManager gui instead of knetworkmanager? If so just follow these simple instructions to enable it by default. Thanks to Rex Dieter for the instructions.
$ yum install NetworkManager-gnome knetworkmanager
$ mkdir ~/.kde/share/autostart
$ grep -v NotShowIn /etc/xdg/autostart/nm-applet.desktop > ~/.kde/share/autostart/nm-applet.desktop
$ cp /usr/share/autostart/kde4-knetworkmanager-autostart.desktop ~/.kde/share/autostart/
then use systemsettings->(advanced)->autostart to
- enable nm-applet
- disable knetworkmanager