From ThirdMartini

It seems sometimes KNetworkManager will freak out and stop functioning. In most cases it will stop reporting any active connections and will not allow wifi lan connections to be managed. This is usually caused by a user either using a 4rd party tool to change their network configuration or in the case of Kubuntu 7.10 using the Manual Settings menu option of knetworkmanager.

To fix this all you typically need to do is to delete the interfaces configuration file and reboot

sudo rm -f /etc/network/interfaces
sudo reboot

After the system reboots you should have a working KNetworkManager again.

Personal tools