--- program/include/rcube_html_page.php~	2009-06-22 11:20:34.000000000 -0500
+++ program/include/rcube_html_page.php	2010-02-01 12:21:44.000000000 -0600
@@ -164,7 +164,13 @@
             $__page_header.= ' content="text/html; charset=';
             $__page_header.= $this->charset . '" />'."\n";
         }
-
+        // add hint to disable DNS prefetching 
+        if (!headers_sent()) { 
+            header('X-DNS-Prefetch-Control: off'); 
+        } else { 
+            $__page_header.= '<meta http-equiv="x-dns-prefetch-control" content="off" />'."\n"; 
+        }
+        
         // definition of the code to be placed in the document header and footer
         if (is_array($this->script_files['head'])) {
             foreach ($this->script_files['head'] as $file) {