SQL-DATABASE ERROR

Database error in WoltLab Burning Board (2.3.6): Invalid SQL: SELECT t.*, p.*, i.*, n.id AS newscat_id, n.title AS newscat_title, n.grafikfile, n.position, b.title AS b_title, b.hotthread_reply AS b_hotthread_reply, b.hotthread_view AS b_hotthread_view, b.postsperpage AS b_postsperpage, b.lastposttime AS b_lastposttime FROM bb2_threads t LEFT JOIN bb2_posts p ON (t.threadid=p.threadid && t.starttime=p.posttime) LEFT JOIN bb2_icons i USING (iconid) LEFT JOIN bb2_boards b ON (b.boardid=t.boardid) LEFT JOIN bb2_portal_newscat n ON (t.newscatid=n.id) WHERE t.visible = 1 AND p.visible = 1 AND t.boardid IN (0,2,20,16,18,14,13,17,15,7,19,9,10,6,8,11,12) AND t.boardid IN (0) ORDER BY t.starttime DESC LIMIT 0,20
mysql error: Column 'iconid' in from clause is ambiguous
mysql error number: 1052
mysql version: 5.1.66-0+squeeze1
php version: 5.2.17
Date: 20.06.2013 @ 00:46
Script: /portal_newscat.php
Referer: