logout error

this module is working so good when im logged in,when i logged out i am getting warning in my pages.can any one pls help me to fix this bug,

user warning: Unknown column 'n.nid' in 'on clause' query: forum_get_forums SELECT DISTINCT(n.nid), l.last_comment_timestamp, IF(l.last_comment_uid != 0, cu.name, l.last_comment_name) as last_comment_name, l.last_comment_uid FROM node n, node_comment_statistics l, users cu, term_node r INNER JOIN node_access na ON na.nid = n.nid WHERE (na.grant_view >= 1 AND ((na.gid = 0 AND na.realm = 'all') OR (na.gid = 1 AND na.realm = 'workflow_access') OR (na.gid = 0 AND na.realm = 'workflow_access_owner'))) AND ( n.nid = r.nid AND r.tid = 28 AND n.status = 1 AND n.type = 'forum' AND l.last_comment_uid = cu.uid AND n.nid = l.nid ) ORDER BY l.last_comment_timestamp DESC LIMIT 0, 1 in