The problem is that in Spain, when you have a Jazztel operator, the APN to configure as if it were Orange.
Although in the apns-conf.xml it appears the operator Jazztel, when the APN is automatically configured as Orange, it selects as MNC 03, when the correct one was 21 and if you try to...
In Spanish language does not let enter the development options.
It activates them correctly and they appear in the menu.
... but when clicked on it gives the message "Settings has stopped".
A greeting.