Strange issue with validation libraries

[eluser]daweb[/eluser]
I don't think this is a problem.

I have the same trouble if I put rules inside my controller:

Code:

function index()
    {
        $data_stack['pageTitle']   = $this->lang->line('titleLogin');
        //$this->load->view('admin/custom_validation/logins_validation.php', '', FALSE);
        $rules['username'] = 'trim|required|min_length[5]|max_length[200]';
        $rules['password'] =   'trim|required|min_length[5]|max_length[200]|callback_check_login';
    $this->validation->set_rules($rules);

    $fields['username'] = $this->lang->line('formUsername');
    $fields['password'] = $this->lang->line('formPassword');
    $this->validation->set_fields($fields);        

if($this->validation->run() == TRUE)
        {
            redirect('front', 'location');
            exit();
        }

        $this->load->view('admin/login/index', $data_stack);
    }

It still doens't works: I have to put-in my settings model to make it work! I can't understand.