Big error at main page of forum module

After installing advanced_forum, I get this error at main page of forum module:

user warning: Every derived table must have its own alias query: SELECT n.title AS topictitle, r.title AS replytitle, r.time timestamp, r.type AS replytype, n.type AS topictype, n.nid AS topicid, t.tid, r.cid AS cid, r.uid, u.name FROM drupal_node AS n INNER JOIN ( (SELECT title, created AS time, nid, uid, type, 'cid' AS cid FROM drupal_node ) UNION (SELECT subject, timestamp, nid, uid, 'comment', cid FROM drupal_comments WHERE drupal_comments.status = 0 ) ORDER BY time DESC ) AS r ON n.nid=r.nid INNER JOIN drupal_term_node AS t ON n.nid = t.nid INNER JOIN drupal_users AS u ON r.uid = u.uid in /home/httpd/vhosts/............../httpdocs/modules/advanced_forum/advanced_forum.module on line 539.

Standard installation, no hacks e.g.

Could anybody fix it and create a new version and package for D6?

Thank you!