mcrypt,<br /> error

Hi,I have just change my config.inc.php from
$cfg['Servers'][$i]['auth_type'] = 'config';
to
$cfg['Servers'][$i]['auth_type'] = 'cookie';
to enable a multi users session for phpMyadmin

I get now the following error Impossible to load extension mcrypt,<br />please check your PHP configuration

Here's my complete config.inc.php file

<?php
/*
* Generated configuration file
* Generated by: phpMyAdmin 3.3.8.1 setup script by Piotr Przybylski <piotrprz@gmail.com>
* Date: Sun, 16 Oct 2011 12:13:03 +0200
*/

/* Servers configuration */
$i = 0;

/* Server: localhost [1] */
$i++;
$cfg['Servers'][$i]['verbose'] = '';
$cfg['Servers'][$i]['host'] = 'localhost';
$cfg['Servers'][$i]['port'] = '';
$cfg['Servers'][$i]['socket'] = '/var/run/mysqld/mysqld.sock';
$cfg['Servers'][$i]['connect_type'] = 'socket';
$cfg['Servers'][$i]['extension'] = 'mysqli';
$cfg['Servers'][$i]['auth_type'] = 'cookie';
$cfg['Servers'][$i]['user'] = '';
$cfg['Servers'][$i]['password'] = '';

/* End of servers configuration */

$cfg['blowfish_secret'] = '4e9aac7281b801.20877280';
$cfg['DefaultLang'] = 'en-utf-8';
$cfg['ServerDefault'] = 1;
$cfg['UploadDir'] = '';
$cfg['SaveDir'] = '';
?>
Something to change in the httpd.conf ?