Looking at this, at the very top of /admin/media_manager.php we have
PHP Code:
 require('includes/application_top.php');

  
$action = (isset($_GET['action']) ? $_GET['action'] : '');  
  
$current_category_id = (isset($_GET['current_category_id']) ? $_GET['current_category_id'] : $current_category_id); 

Perhaps if we spiced that up a bit...
PHP Code:
 require('includes/application_top.php');

  
$action = (isset($_GET['action']) ? $_GET['action'] : '');
$categories_id_check $db->Execute("select c.categories_id, cd.categories_name, c.parent_id
                                from " 
TABLE_CATEGORIES " c, " TABLE_CATEGORIES_DESCRIPTION " cd
                                where c.categories_id = cd.categories_id
                                and cd.language_id = '" 
. (int)$_SESSION['languages_id'] . "'
                                and c.parent_id = '0'
                                order by c.sort_order, cd.categories_name"
);
  if(
$categories_id_check->RecordCount()>0)
      
$current_category_id $categories_id_check->fields['categories_id'];
$current_category_id = (isset($_GET['current_category_id']) ? $_GET['current_category_id'] : $current_category_id);