PHP 4 e MySQL 5: Client does not support authentication protocol requested by server

[Gionnico]

Ho installato da poco questi due programmi.

Ho configurato php per interagire con apache.

Ho provato a far connettere (con modulo mysql) il database con questo codice:

<?php
  require ($_SERVER["DOCUMENT_ROOT"] . "/data_config.php");
  $connection = mysql_connect ($db_host, $db_user, $db_password) or die("error connecting");
  echo "connection made";
?>

Ma ricevo quest'errore:

Warning: mysql_connect(): Client does not support authentication protocol requested by server; consider upgrading MySQL client in c:\apèache\connessione.php on line 3
error connecting