undefined property

[eluser]f0n3man[/eluser]
i am having a problem getting an error message from the controller that the property Site::$site_model is undefined. the php error in the system log states: 'Call to a member function get_records() on a non-object in /path/etc...'. the get_records function exists in site_model.php. i have the database library autoloaded, and even have the model loaded in the controller, and still get the same error message. i have done this in two different installations with 2 different versions. i can access the database and pull records. from the controller. i am brand new to codeigniter, but so far am not impressed as i can't get it to work properly. any other ideas?