CodeIgniter customer Controller class says session is undefined

[DeathSoul]

I'm using CodeIgniter (v1.7.2) and I've created a custom controller that incorporates authentication called MY_Controller (based on David Winter's blog post). When I load any controllers that use this base class, I get this error;\[quote\] *Message: Undefined property: MY_Controller::$session*\[/quote\]Note that I am autoloading 'session' (and 'MY_controller' as a library) like so:\[code\]$autoload['libraries'] = array('database', 'session', 'MY_Controller');\[/code\]Here is MY_Controller:\[code\]class MY_Controller extends Controller { public function __construct() { parent::__construct(); if (!$this->session->userdata('loggedin')) { <-- error is here header('Location: /sessions/login'); exit(); } }}\[/code\]Here's the controller that I'm trying to load:\[code\]class Welcome extends MY_Controller { function __construct() { parent::__construct(); } function index() { $this->load->view('header'); $this->load->view('welcome_message'); $this->load->view('footer'); }}\[/code\]When I var_dump \[code\]$this->session\[/code\] above where the error occurs, I can see that it is NULL. Even putting \[code\]$this->load->library('session');\[/code\] in MY_Controller's constructor doesn't work. Why isn't it loading properly?Thanks