Where is comment admistration template located?
If, for some reason, the whole Author fieldset is hidden, be sure to check the HTML first, then you can also use the devel module for some dpm-ing in yourtheme_form_comment_form_alter.

Something like this should force the fieldset to be rendered:

function yourtheme_form_comment_form_alter(&amp;$form, &amp;$form_state) { 
  $form['author']['#access'] = user_access('administer comments');
}