SQL-DATABASE ERROR

Database error in WoltLab Burning Board: Invalid SQL: SELECT e.*, g.chgpermission, cc.*, re.* FROM bb1_events e LEFT JOIN bb1_users u USING (userid) LEFT JOIN bb1_groups g USING (groupid) LEFT JOIN bb1_events_ret re ON (e.eventid=re.eventid) LEFT JOIN bb1_cal_cats cc ON (e.catid=cc.catid) WHERE (public='1' AND ((FIND_IN_SET('5',e.permission)>0 OR e.permission='') AND FIND_IN_SET('5',g.chgpermission)>0) OR e.userid=0) AND ((ret_enddate>='2012-02-01' OR ret_enddate<=eventdate) AND eventdate<='2012-02-29' AND (MOD(PERIOD_DIFF(DATE_FORMAT(e.eventdate,'%y%m'),20122),retval)=0 AND retmode='month' OR (MOD(PERIOD_DIFF(DATE_FORMAT(e.eventdate,'%y%m'),201202),(retval*12))=0 AND retmode='year') OR retmode!='year' AND retmode!='month') OR MONTH(eventdate)='2' AND YEAR(eventdate)='2012' AND re.retmode IS NULL)
mysql error: Column 'groupid' in from clause is ambiguous
mysql error number: 1052
Date: 07.02.2012 @ 12:04
Script: /calender.php
Referer: