Only Load Model in construct ??? Why

[eluser]n0xie[/eluser]
Can you show me your code? I just tried it and it works fine:

Code:

/* controllers/test.php */
class Test extends Controller {
    function Test() {
        parent::Controller();

    }

    function index(){
        $this->load->model('User_model');
        $this->User_model->a();
    }

Code:

/* models/user_model.php */
class User_model extends Model{

    function User_model(){
        parent::Model();
    }

    function a(){
        echo 'a';
    }
}