I'm trying to connect to my school network from Ubuntu 12. The network is WPA encrypted and I can connect just fine if the network manager establishes a connection automatically. However, when I get disconnected and try to reconnect a username and password prompt pops up. The credentials are already stored and are autofilled in correctly, but the Connect button is disabled so I can't actually connect to the network.
What can I do? The only guess I've found so far is the password is too short and Ubuntu is expecting a full WPA key. I don't administer the school network though so I certainly can't change that.