SQL-DATABASE ERROR

Database error in WoltLab Burning Board: Invalid SQL: SELECT e.*, g.chgpermission, cc.*, re.* FROM bb84_events e LEFT JOIN bb84_users u USING (userid) LEFT JOIN bb84_groups g USING (groupid) LEFT JOIN bb84_events_ret re ON (e.eventid=re.eventid) LEFT JOIN bb84_cal_cats cc ON (e.catid=cc.catid) WHERE (public='1' OR e.userid=0) AND ((ret_enddate>='2010-03-01' OR ret_enddate<=eventdate) AND eventdate<='2010-03-31' AND (MOD(PERIOD_DIFF(DATE_FORMAT(e.eventdate,'%y%m'),20103),retval)=0 AND retmode='month' OR (MOD(PERIOD_DIFF(DATE_FORMAT(e.eventdate,'%y%m'),201003),(retval*12))=0 AND retmode='year') OR retmode!='year' AND retmode!='month') OR MONTH(eventdate)='3' AND YEAR(eventdate)='2010' AND re.retmode IS NULL)
mysql error: Column 'groupid' in from clause is ambiguous
mysql error number: 1052
Date: 12.03.2010 @ 03:30
Script: /calender.php
Referer: