I'm curious in knowing how do you know which is my webpage is, but guess that's not important

.
I have no errors of any kind. When I try to login with facebook it just redirect me to the registration form with some fb accounts, and with others it really loged in automatically. I have maximum error reporting and here is what the log says:
#
#<?php die('Forbidden.'); ?>
#Date: 2015-08-21 18:44:24 UTC
#Software: Joomla Platform 13.1.0 Stable [ Curiosity ] 24-Apr-2013 00:00 GMT
#Fields: datetime priority clientip category message
2015-08-21T18:44:24+00:00 INFO 186.62.147.40 jfbconnect Settings updated!
2015-08-21T18:45:43+00:00 INFO 186.62.147.40 jfbconnect Perfil de Facebook conectado con éxito. (This one is the automatically registered)
2015-08-21T18:53:51+00:00 INFO 186.62.147.40 jfbconnect Perfil de Facebook conectado con éxito. (In this one, I completed the registration form)
In all, I tried with 10 accounts, 4 of them automatically registered, and 6 of them redirected me to the registration form. I just wanted to know if it depends on facebook, or if there is any way in which I can force EVERY registration via facebook to be automatic.