Extending the controller class

[eluser]richzilla[/eluser]
thanks for the help, ive tried the suggestions mentioned there, but still no luck. so far i have:

a MY_Controller:

Code:

class MY_Controller extends Controller {
    
    function __construct() {
        parent::Controller();
    }
    
    
}

A Site_Controller:

Code:

class Site_Controller extends MY_Controller{
    
    function __construct() {
        parent::MY_Controller();
        
    }

and an Admin_Controller:

Code:

class Admin_Controller extends MY_Controller {

    function Admin_Controller() {
        parent::MY_Controller();
    }

but still no luck, it should be noted that if simply extend my usual controllers directly from the Controller class, they work without a hitch, so my code is ok. Also on a slightly different note, what is the purpose of this :

Code:

function __autoload($class)
{
if(strpos($class, 'CI_') !== 0)
{
  @include_once( APPPATH . 'libraries/'. $class . EXT );
}
}

Any help would be appreciated.