Comments Confusion

styles.css > line 537: (span.poster-roles)

You haven’t defined …

• any offset to differ between author and admin for the sprite (author/admin)
• any additional class to make a difference between author/admin

It seems that you wanted to only add the graphic for registered authors and admins (there’s nothing for guests).

You’ll need to add …

(on top of your comments template/file)
global $current_user;
get_currentuserinfo();
$user_ID = $current_user->user_ID;
$the_user = get_userdata( $user_ID );

(inline – comment div)
a class for authors & admins like

<span class="<?php   
if ( !empty($the_user) ) :  
  echo $the_user->wp_capabilities->role;   
else :  
  echo 'guest';  
endif;  
?>">

Then do some offset for the class mentioned above like

ol.commentlist li.comment ul.children li.comment-author-admin .poster-roles.admin { 
   background-position: 0px 0px;
}  
ol.commentlist li.comment ul.children li.comment-author-admin .poster-roles.author {
   background-position: 0px -40px;
}

I don’t know exactly if it’s wp_capabilities->roles, so please refer to some of my old (since a long time not further developed) plugins for the exact user info – your friendly current user deamon.