shortcodes not working with wordpress 3.3.2

Hello,

I have this problem. In one server I have wordress 3.3.1 and my shortcodes are working perfectly, but they aren’t in wordpress 3.3.2. This is what wordpress is printing: [CONFIRMATION_MESSAGE]

and this is the code:

function confirmation_message($atts) {
extract(shortcode_atts(array(
‘_confirmation’ => ”
), $atts));

return “{$this->message}”;
}

Then:
add_shortcode(‘CONFIRMATION_MESSAGE’, array(&$this, ‘confirmation_message’));

What you suggest for fixing this problem?