Index: modules/forum/forum.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/forum/forum.module,v
retrieving revision 1.527
diff -u -p -r1.527 forum.module
--- modules/forum/forum.module	23 Oct 2009 22:24:14 -0000	1.527
+++ modules/forum/forum.module	24 Oct 2009 04:09:54 -0000
@@ -1108,14 +1108,14 @@ function _forum_update_forum_index($nid)
 
   if ($count > 0) {
     // Comments exist.
-    $last_reply = db_query_range('SELECT cid, name, timestamp, uid FROM {comment} WHERE nid = :nid AND status = :status ORDER BY cid DESC', array(
+    $last_reply = db_query_range('SELECT cid, name, created, uid FROM {comment} WHERE nid = :nid AND status = :status ORDER BY cid DESC', 0, 1, array(
       ':nid' => $nid,
       ':status' => COMMENT_PUBLISHED,
-    ), 0, 1)->fetchObject();
+    ))->fetchObject();
     db_update('forum_index')
       ->fields( array(
         'comment_count' => $count,
-        'last_comment_timestamp' => $last_reply->timestamp,
+        'last_comment_timestamp' => $last_reply->created,
       ))
       ->condition('nid', $nid)
       ->execute();