Can't autoload file in Packages

Hi.
This is the my config
application/config/autoload.php

PHP Code:

$autoload['packages'] = array(APPPATH.'third_party/my_package'); 


in application/third_party/core/config/autoload.php
i config:

PHP Code:

require_once(APPPATH.'third_party/my_package/libraries/my_lib.php'); 


My file exitst but can't loaded file my_lib.php

pls help me.
(sr my eng)