--- subscribers.php     2008-01-27 17:37:46.000000000 +0000
+++ /var/www/moodle/mod/forum/subscribers.php   2008-01-27 17:26:55.000000000 +0000
@@ -139,11 +139,7 @@
 
 /// If no search results then get potential subscribers for this forum excluding users already subscribed
     if (empty($searchusers)) {
-        if ($currentgroup) {
-            $users = get_group_users($currentgroup, 'firstname ASC, lastname ASC', $subscriberlist);
-        } else {
-             $users = get_course_users($course->id, 'firstname ASC, lastname ASC', $subscriberlist);
-        }
+        $users = get_users_by_capability($context,'mod/forum:view', 'id, firstname, lastname, email', 'firstname ASC, lastname ASC', '', '', $currentgroup, $subscriberlist);
         if (!$users) {
             $users = array();
         }