search.php sends redirects using the code below.
header('Location: search.php?search_id='.$search_id);As you can see the location is a relative URI. According to the http specification location must be an absolute URI.
It's fairly common to send relative redirects like above and I haven't seen any browser have any problem with it but it's really easy to fix. Replacing the line above with the follow makes the location absolute. I haven't seen it cause any problem.
header('Location: '.$pun_config['o_base_url'].'/search.php?search_id='.$search_id);