title: Why drupal_render($form) does not render correctly RADIOS #type?
body: <p>I'm trying to use <strong><a href="http://api.drupal.org/api/drupal/includes--form.inc/function/drupal_render_form/6" rel="nofollow">drupal_render()</a></strong> to render a single form element. I can successfully render elements of <code>'#type' =&gt; 'textfield' or 'radio' or 'whatever'</code>.  </p>
  
  <p>When I try to render an element of <code>'#type' =&gt; 'radios'</code> something goes wrong. I can't find out why but the radios simple won't show.</p>
  
  <pre><code>$options = array(
      '0' =&gt; 'no option',
      '1' =&gt; 'option 1',
      '2' =&gt; 'option 2',
      '3' =&gt; 'option 3',
      '4' =&gt; 'option 4',
      '5' =&gt; 'option 5'
  );
  
  $form['radiosinput'] = array(
      '#type'             =&gt; 'radios',
      '#title'            =&gt; 'radios title',
      '#description'      =&gt; 'radios description',
      '#default_value'    =&gt; 0,
      '#options'          =&gt; $options,
      '#required'         =&gt; TRUE,
  );
  
  var_dump( drupal_render($form) );
  
  // string(257) "&lt;div class="form-item"&gt;
  //     &lt;label&gt;radios title: &lt;span class="form-required" title="This field is required."&gt;*&lt;/span&gt;&lt;/label&gt;
  //     &lt;div class="form-radios"&gt;&lt;/div&gt;
  //     &lt;div class="description"&gt;radios description&lt;/div&gt;
  //     &lt;/div&gt;
  // "
  </code></pre>
  
  <p><strong>Anyone knows what's the problem and the fix/workaround?</strong><br>
  Is there any known problem with rendering radios or something?</p>
  
  <p>Thanks!</p>