CodeIgniter Datamapper ORM: Error with relationship by using get() -

i have problem datamapper orm in codeigniter... :o

my first model:

class mil_widget extends datamapper {      // insert related models mil_widget can have more 1 of.     var $has_many = array(          'mil_relationship' => array(             'join_table' => 'mil_fields_mil_widgets'         )     ); } 

and other model:

class mil_relationship extends datamapper {      // insert related models mil_widget can have more 1 of.     var $has_many = array(          'mil_widget' => array(             'join_table' => 'mil_fields_mil_widgets'         )     ); } 

if di works , saves right database entry:

$w = new mil_widget(1); $r = new mil_relationship(1); $w->save($r); 

but if error:

$w->mil_relationship->get(); 

and error:

datamapper error: 'mil_widget' not valid parent relationship mil_relationship. relationships configured correctly?

thank you!