Aşağıdaki kodlarla ben sorunsuz işlem yapıyorum.

İsteyen cURL kullanıp proxy ekleyebilir.
<?php
/*
* SAINTX » XYZ BOT
*
* @author: SAINTX
* @web: http://saintx.net
* @mail: im@saintx.net
* @date: 16.08.2013
* @version: 1.0.0
*/
function get_redtube_video_url($ID) {
$try = true;
while($try) {
$html = file_get_contents(sprintf('http://www.redtube.com/%s', $ID));
$video_url = preg_match('#flv_h264_url\=(.*?)\&#si', $html, $matches) ? urldecode(end($matches)) : '';
unset($html, $matches);
if(!strstr($video_url, 'http://vid.lsw.redtubefiles.com/'))
$try = false;
}
unset($try);
return $video_url;
}
header(sprintf('Location: %s', get_redtube_video_url($_GET['ID'])));