Auth-1.1.1.tgz -- Function Not Found.

Hello. I am now using a Debian Unstable version, newly downloaded the Auth-1.1.1.tgz to use. I copied the example 2 from the manual for testing. But found the below error. Fatal error: Call to undefined function: isconnection() in /usr/share/pear/Auth/Container/DB.php on line 133 The code from the Container/DB.php are as below

    function query($query)
    {
        if (!DB::isConnection($this->db)) {		<-- line 133
            $this->_connect($this->options['dsn']);
        }
        return $this->db->query($query);
    }

Please help. Thanks. ~Pat.