Comment 7 for bug 95343

Kat and Tony - Feisty ships with network-manager a tool that was not included with Edgy. network-manager is designed to: "NetworkManager attempts to keep an active network connection available at all times. It is intended only for the desktop use-case, and is not intended for usage on servers. The point of NetworkManager is to make networking configuration and setup as painless and automatic as possible". By having your wireless networks configured in '/etc/network/interfaces' network-manager will not manage the devices and this can cause a conflict. I recommend removing the configuration lines from '/etc/network/interfaces' and allowing network-manager to configure the interface with the essid and wep key.