Another WordPress problem from me!

I have been trying to setup two custom taxonomies in WordPress 2.8 for "Course subject" and "Kind of chance".

I made use of this code in functions.php:

function create_pc_db_taxonomies() {
    register_taxonomy( 'course', 'post', array(
        'hierarchical' => false,
        'label' => __('Course subject', 'series'),
        'query_var' => 'course',
        'rewrite' => array( 'slug' => 'courses' )
    ) );

    register_taxonomy( 'type', 'post', array(
        'hierarchical' => false,
        'label' => __('Type of opportunity', 'series'),
        'query_var' => 'type',
        'rewrite' => array( 'slug' => 'types' )
    ) );
}

which works absolutely fine, however i want hierarchical (category-style) admin boxes instead of tag-style admin boxes.

However, after i set 'hierarchical' => true to ensure that the above mentioned code becomes:

function create_pc_db_taxonomies() {
    register_taxonomy( 'course', 'post', array(
        'hierarchical' => true,
        'label' => __('Course subject', 'series'),
        'query_var' => 'course',
        'rewrite' => array( 'slug' => 'courses' )
    ) );

    register_taxonomy( 'type', 'post', array(
        'hierarchical' => true,
        'label' => __('Type of opportunity', 'series'),
        'query_var' => 'type',
        'rewrite' => array( 'slug' => 'types' )
    ) );
}

I recieve no boxes whatsoever.

Shall We Be Held doing a problem?

It's working but there is not any admin UI instantly built-in Wordpress-Admin, based on Trac "Support is going to be added later"