Unknown column 'o.register' on path user/register

PHP error when visiting path user/register

Unknown column 'o.register' in 'where clause' query: og_user /* Anonymous : og_user */ SELECT n.nid, n.title, o.* FROM node n INNER JOIN og o ON n.nid = o.nid WHERE ((n.moderate != 1)) AND ( n.type IN ('page') AND n.status = 1 AND o.register = 1 )ORDER BY n.title in /drupal-6/sites/all/modules/og/og.module on line 2359.