Errors in the database

I have set my default domaing name settings at "All: all domains, including the default, see only their own content" and now I am getting error on Forum pages and Directory pages as well

user warning: Not unique table/alias: 'tn' query: SELECT ncs.last_comment_timestamp, IF (ncs.last_comment_uid != 0, u2.name, ncs.last_comment_name) AS last_comment_name, ncs.last_comment_uid FROM node n INNER JOIN users u1 ON n.uid = u1.uid INNER JOIN term_node tn ON n.nid = tn.nid INNER JOIN node_comment_statistics ncs ON n.nid = ncs.nid INNER JOIN users u2 ON ncs.last_comment_uid=u2.uid INNER JOIN term_node tn ON tn.nid = n.nid WHERE (tn.tid = 160) AND ( n.status = 1 AND n.type='forum' AND tn.tid = 93 ) ORDER BY ncs.last_comment_timestamp DESC LIMIT 0, 1 in /home/ilru07/public_html/includes/database.mysql.inc on line 172.

The error is much bigger you can take a look at it by visiting this link http://www.ilru.net/forum