Error with the encode password function

[eluser]jgodino[/eluser]
Yes. I have a key in my config.php.

/*
|--------------------------------------------------------------------------
| Encryption Key
|--------------------------------------------------------------------------
|
| If you use the Encryption class or the Sessions class with encryption
| enabled you MUST set an encryption key. See the user guide for info.
|
*/
$config['encryption_key'] = "encryption_key_Gg2F55454";