While using following template, I am losing my 'active state' status within the menu (>> The Basically switch templates (within the edit>post form), I actually do possess the active condition.

<?php
/**
 * Template Name: Important dates
 * Description: All dates
 *
 * @package WordPress
 * @subpackage Test
 */

get_header(); ?>
        <div id="primary">
            <div id="content" role="main" class="yellow">


<ul class="data">
<?php
// query the posts of your custom post types
query_posts( array(
        'post_type' => array(
                    'datum'
                ),
                'order' => 'ASC' ) // for paging links to work
            );  

// have some posts?
if (have_posts()) :
    while (have_posts()) : the_post(); // begin the Loop
?>
    <li><?php the_title(); ?></li>
<?php
}   
    endwhile;
endif;
?>
</ul>



            </div><!-- #content -->
        </div><!-- #primary -->

<?php get_sidebar(); ?>
<?php get_footer(); ?>

Does anybody know why &lifier where it is going wrong?

Thx ahead of time!