--- comment_subscribe/comment_subscribe.module.orig	2008-12-27 19:31:22.000000000 +0300
+++ comment_subscribe/comment_subscribe.module	2008-12-27 19:31:35.000000000 +0300
@@ -328,7 +328,7 @@
     //or node comments.
     if ( $GLOBALS['db_type']=='pgsql') {
       $result = db_query(
-             "SELECT DISTINCT c.cid,u.init,c.uid,c.name,c.nid, ".
+             "SELECT DISTINCT on (mail) c.cid,u.init,c.uid,c.name,c.nid, ".
              "  (case when length(c.mail)<1 then coalesce (u.mail,u.init) else c.mail end) AS mail ".
              " FROM {comments} c LEFT OUTER JOIN {users} u ON u.uid=c.uid ".
            " LEFT JOIN {z_commentsubscribe} zc on zc.cid=c.cid ".