Fijate aca abajito que si tu hosting es Windows no funcionan algunas cosillas:
http://www.php.net/manual/es/functio...nsrr.php#30692 Cita: The checkdnsrr function is not implemented on the Windows platform. The way to get around this problem is to write your own version of checkdnsrr.
el mio era linux, sigo buscando ...