Show Posts AND Custom Post Type of same category

Hi everybody,

I want to show posts AND Custom Post Type of same category on a page and can′t figure it out. Show either one or the other works, but not both.
My guess was:

<?php $paged = (get_query_var('my_category')) ? get_query_var('my_category') : 1; query_posts(array(
	'post_type' => array ('my_custom_post_type','posts'),
	'paged'=>$paged,
	));
?>

, but this only shows the cpt-entries.
In my functions.php:

function post_type_projects()
{
	register_post_type('my_custom_post_type',
		array(
			'label' => __('My_custom_post_type'),
			'public' => true,
			'show_ui' => true,
			'taxonomies' => array('category'),
			'menu_position' => 5,
			'supports' => array(
				'title',
		    	'editor',
				'thumbnail',
				'revisions'
			),
		  'query_var' => true
		)
	);
}
add_action( 'init', 'post_type_projects' );

Anybody got a hint how to do this? Thanks in advance.

Uli