Problems with RPi

[Pulpo]

Hello, when I follow this guide: http://minepeon.com/index.php/WiFi

Everything goes well until I get to the part where I have to configure my own wifi. I choose WEP encryption, and when I save, for some reason it saves every change except the type of encryption, which resets to WPA again, I have tried to change this 5 times and still goes back to WPA after choosing WEP in configuration. I have also tried restarting and configurating again, but still the same problem.

Help please!