Hooks Not Working Correct

I have enabled hooks. 

And I use a pre_controller

PHP Code:

$hook['pre_controller'] = array(
    'class' => 'Maintenance',
    'function' => 'index',
    'filename' => 'Maintenance.php',
    'filepath' => 'controllers/common/',
); 


PHP Code:

<?php

class Maintenance extends CI_Controller {

    public function index() {
        if ($this->config->item('maintenance') == TRUE) {
            $this->load->view('theme/default/template/common/maintenance_view');
        }
    }
} 


When the maintenance config item is true it should over ride the current view and display maintenance view. But does not still displays the home controller view.

I have autoloaded my setting.php config file

PHP Code:

<?php

$config['maintenance'] = TRUE; 


Then when is false should disable it.

There's only one rule - please don't tell anyone to go and read the manual.  Sometimes the manual just SUCKS!