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

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');

        }