Cant extend Session library

[eluser]Nekluh[/eluser]
Hi!

I'm converting to the latest codeigniter 2.02 and suddenly I can't extend the Session library.

I have the MY_Session.php in the /core/ folder and it looks like this

Code:

class MY_Session extends CI_Session {

    function __construct()
    {
        parent::__construct();
        echo "In extended session";
    }
}

I can extend the Controller and Model class without any problems.
Does anybody have the same problem? Ideas?