by Vincent Ogloblinsky.
First solution found to prevent displaying the "match signature" error :
Comment this block
if (!$matched) {
require_once 'Zend/XmlRpc/Server/Exception.php';
throw new Zend_XmlRpc_Server_Exception('Calling parameters do not match signature', 623);
}
in moodle/lib/zend/Zend/XmlRpc/Server.php ; line 595