title: Custom taxonomy "hierarchical' => true" not working in WordPress 2.8
body: <p>Another WordPress issue from me!</p>
  
  <p>I've been trying to set up two custom taxonomies in WordPress 2.8 for "Course subject" and "Type of opportunity".</p>
  
  <p>I used this code in functions.php:</p>
  
  <pre><code>function create_pc_db_taxonomies() {
      register_taxonomy( 'course', 'post', array(
          'hierarchical' =&gt; false,
          'label' =&gt; __('Course subject', 'series'),
          'query_var' =&gt; 'course',
          'rewrite' =&gt; array( 'slug' =&gt; 'courses' )
      ) );
  
      register_taxonomy( 'type', 'post', array(
          'hierarchical' =&gt; false,
          'label' =&gt; __('Type of opportunity', 'series'),
          'query_var' =&gt; 'type',
          'rewrite' =&gt; array( 'slug' =&gt; 'types' )
      ) );
  }
  </code></pre>
  
  <p>which works absolutely fine, but I want hierarchical (category-style) admin boxes rather than tag-style admin boxes.</p>
  
  <p>However, when I set <code>'hierarchical' =&gt; true</code> so that the above code becomes:</p>
  
  <pre><code>function create_pc_db_taxonomies() {
      register_taxonomy( 'course', 'post', array(
          'hierarchical' =&gt; true,
          'label' =&gt; __('Course subject', 'series'),
          'query_var' =&gt; 'course',
          'rewrite' =&gt; array( 'slug' =&gt; 'courses' )
      ) );
  
      register_taxonomy( 'type', 'post', array(
          'hierarchical' =&gt; true,
          'label' =&gt; __('Type of opportunity', 'series'),
          'query_var' =&gt; 'type',
          'rewrite' =&gt; array( 'slug' =&gt; 'types' )
      ) );
  }
  </code></pre>
  
  <p>I get no boxes at all.</p>
  
  <p>Am I doing something wrong?</p>