Index: boxes.module
===================================================================
--- boxes.module	(revisión: XXXX)
+++ boxes.module	(copia de trabajo)
@@ -152,11 +152,9 @@
 function boxes_footer() {
   // Besure the page isn't a 404 or 403.
   $headers = drupal_set_header();
-  foreach (explode("\n", $headers) as $header) {
-    if ($header == "HTTP/1.1 404 Not Found" || $header == "HTTP/1.1 403 Forbidden") {
+  if ($headers[':status'] == "404 Not Found" || $headers[':status'] == "403 Forbidden") {
       return;
     }
-  }
 
   if (!empty($_GET['boxes_delta']) && boxes_access_admin()) {
     ctools_include('ajax');