--- timthumb.php    2011-08-02 08:15:25.000000000 -0700
+++ timthumb.new    2011-08-02 11:08:55.000000000 -0700
@@ -641,7 +641,9 @@
                display_error ('source filename invalid');
            }

-           if (($url_info['host'] == 'www.youtube.com' || $url_info['host'] == 'youtube.com') && preg_match ('/v=([^&]+)/i', $url_info['query'], $matches)) {
+           $url_host = preg_replace( '/^www\./', '', strtolower( $url_info['host'] ) );
+
+           if ( $url_host == 'youtube.com' && preg_match ('/v=([^&]+)/i', $url_info['query'], $matches) ) {
                $v = $matches[1];
                $src = 'http://img.youtube.com/vi/' . $v . '/0.jpg';
                $url_info['host'] = 'img.youtube.com';
@@ -650,19 +652,10 @@
            $isAllowedSite = false;

            // check allowed sites (if required)
-           if (ALLOW_EXTERNAL) {
-
+           if (ALLOW_EXTERNAL)
                $isAllowedSite = true;
-
-           } else {
-
-               foreach ($allowedSites as $site) {
-                   if (preg_match ('/(?:^|\.)' . $site . '$/i', $url_info['host'])) {
-                       $isAllowedSite = true;
-                   }
-               }
-
-           }
+           else
+               $isAllowedSite = (bool)count( preg_grep( '/^' . preg_quote( $url_host ) . '$/i', $allowedSites ) );

            // if allowed
            if ($isAllowedSite) {
@@ -861,4 +854,4 @@
    echo '<br />TimThumb version : ' . VERSION . '</pre>';
     die ();

-}
\ No newline at end of file
+}