Pour commencer creez un fichier, inserez y les code ci-dessou, nommez le titledata.php et enregistrez le dans

votre_rep_mambo/includes/

code:
<?php
// titledata.php
/**
// Based on metadata.php - recoded  by konlong and chipjack
* @package Mambo Open Source
* @Copyright (C) 2000 - 2003 Miro International Pty Ltd
* @ All rights reserved
* @ Mambo Open Source is Free Software
* @ Released under GNU/GPL License : http://www.gnu.org/copyleft/gpl.html
**/

defined( '_VALID_MOS' ) or die( 'Direct Access to this location is not allowed.' );

function showTitle( &$database, $option) {

  $task = mosGetParam( $_REQUEST, 'task', 0);
  $pageTitle = '';

  if ($option == 'content') {
    $id = mosGetParam( $_REQUEST, 'id', 0 );
    if ($id) {
      switch ($task) {
        case "view":
          $row = new mosContent( $database );
          $row->load( $id );
          $pageTitle = $row->title_alias;
          if($pageTitle == '') {
            $pageTitle = $row->title;
          }
          break;
        case "category":
        case "blogcategory":
        case "archivecategory":
          $row = new mosCategory( $database );
          $row->load( $id );
          $pageTitle = $row->title;
          break;
        case "section":
        case "blogsection":
        case "archivesection":
          $row = new mosSection( $database );
          $row->load( $id );
          $pageTitle = $row->title;
          break;
        default:
          break;
      }
    }
  }else {
    $id = mosGetParam( $_REQUEST, 'Itemid', 0 );
    if ($id) {
         $row = new mosMenu( $database );
         $row->load( $id );
         $pageTitle = $row->name;
      }
   }
  echo $pageTitle;
}
showTitle( $database, $option );
?>

Dans le fichier index.php de votre template actif, ( votre_rep_mambo/templates/votre_template_actif/index.php ) 

inserez / remplacez le code ci-dessou :

code:
<title><?php echo $mosConfig_sitename; ?> <?php include ("includes/titledata.php"); ?></title>

©
Ni ce code, ni son utilisation sont de moi, mais il existe plusieurs copies de ce texte sur differents sites, donc il m'est impossible de vous indiquer qui en  est l'auteur.