Need Help... problem with hmvc and form_validation callback....

[eluser]psychoder[/eluser]
hello guys, my form validation callbacks seems not triggered...
here is the codes... im using hmvc

controller

Code:

$this->form_validation->set_rules('name', 'Name', 'required');
        $this->form_validation->set_rules('email', 'Email', 'required|valid_email');
        $this->form_validation->set_rules('message', 'Message', 'required');
        $this->form_validation->set_rules('captcha', 'Captcha', 'required|callback__captcha_check');

        if ($this->form_validation->run() == true)
        {
            $message = array(
                'username' => $this->input->post('name'),
                'email' => $this->input->post('email'),
                'message' => $this->input->post('message'),
                'date_send' => now(),
                'status' => 0
            );
            $this->messages_model->insert_message($message);
            $this->session->set_flashdata('contact_error', 'Message Sent...');
            $this->session->set_flashdata('success', TRUE);
            redirect('contact');
        }
        else
        {
            if ($this->captcha->create())
            {
                $data['captcha'] = $this->_captcha_img_html($this->captcha->html_data);
            }
            else
            {
                $data['captcha'] = 'Captcha : ' . $this->captcha->debug;
            }
            $data['error'] = (validation_errors()) ? validation_errors() : $this->session->flashdata('contact_error');
            $data['success'] = $this->session->flashdata('success') ? $this->session->flashdata('success') : FALSE;
            $data['uname'] = array(
                'name' => 'name',
                'class' => 'input_text ui-widget-content ui-corner-all',
                'value' => $this->form_validation->set_value('name')
            );
            $data['email'] = array(
                'name' => 'email',
                'class' => 'input_text ui-widget-content ui-corner-all',
                'value' => $this->form_validation->set_value('email')
            );
            $data['captcha_t'] = array(
                'name' => 'captcha',
                'class' => 'input_text ui-widget-content ui-corner-all'
            );
            $data['message'] = array(
                'name' => 'message',
                'class' => 'form_textarea ui-widget-content ui-corner-all',
                'value' => $this->form_validation->set_value('message')
            );

          
            $this->template
                    ->title('example', 'Contact ')
      
                    ->set_partial('menu', 'partials/menu')
                    ->set_partial('footer', 'partials/footer')
                    ->set_partial('content', 'partials/contact_form', $data)
                    ->build('dummy');
        }

callback

Code:

function _captcha_check($captcha)
    {
        if ($this->captcha->check($captcha))
        {
            return TRUE;
        }
        else
        {
            $this->form_validation->set_message('_captcha_check', 'Please enter the word correctly.');
            return FALSE;
        }
    }