The thing is post_ID_list already ordered the way [u]I want[/u]. And I expect the results list ordered the same way, but they always ordered by post_ID ? Is there any way to stop it without hacking the core?

I tried using combinations of 'order' and 'orderby' without any luck.

$adv_MainList = & new ItemList2( $Blog, NULL, NULL, $this->Settings->get('posts_per_page') );
$adv_MainList->set_filters( array(
		'types'			=>	NULL,
		'page'			=>	$this->paged,
		'post_ID_list'	=>	implode( ',', array_keys($matched_posts) ),
	), false ); // do not memorize