Ti.Contacts.getAllPeople() return null

Hello,

I am using Ti.Contacts.getAllPeople() but it returns null when I use it just after installing the app.

I am checking previously If I have rights to read the agenda and everything seems to be right:

if (Ti.Contacts.contactsAuthorization == Ti.Contacts.AUTHORIZATION_AUTHORIZED){
    var contacts = Ti.Contacts.getAllPeople();
}

Any suggestion?

Thanks. J. Pablo.