how to sort a blog view by diggie points in Expression Engine

Question

i need to embed a blog in a template in expression engine and want the result to be sorted by diggie votes. this is what i have right now and it seems to only sort by random:

 {reverse_related_entries weblog="contest_photos" orderby="vote_count" sort="asc" dynamic="off"}
 <li>
     <a href="{title_permalink=photos}"><img src="{site_url}phpThumb.php?src={photo_url}" alt="" /></a>
     <div class="caption">
         <h4><a href="{title_permalink=photos}">{title}</a></h4>
     <p><a href="{path=user/profile/{username}}">{username}</a></p>
     </div>
 </li>

{/reverse_related_entries}