I’ve always had problems with the gnome and kde network managers. They did some funny things and were autoconnecting to things I did not want them to auto connect to. Using the built in command line network tools like ifconfig and iwconfig worked well, but the gui tools were never quite right until I found a replacement called Wicd. In my few days of use, back and forth between wifi and wired networks, i’ve found that wicd just works. It’s a pygtk program, so it needs python and the python gtk bindings, which probably makes it less desirable to include in a distro than the default C/gtk tools, but it works much better than those default gui tools.