MySQL ERROR:

Error Number: 1109

Description: Unknown table 'md' in field list

Query: SELECT t.topic_id, t.author_id, t.title, t.body, t.topic_date, t.thread_total, t.last_post_author_id, t.last_post_date, t.topic_edit_date, t.parse_smileys, f.forum_html_formatting, f.forum_auto_link_urls, f.forum_allow_img_urls, m.screen_name AS last_post_author, a.screen_name AS author, a.email, a.url, md.m_field_id_1 AS author_organisation, md2.m_field_id_1 AS last_post_author_organisation FROM exp_forum_topics t, exp_forums f, exp_members m, exp_members a WHERE t.last_post_author_id = m.member_id AND f.forum_id = t.forum_id AND a.member_id = t.author_id AND md.member_id = t.author_id AND md2.member_id = t.last_post_author_id AND t.announcement = 'n' AND (t.forum_id IN (7) OR t.moved_forum_id IN (7)) ORDER BY last_post_date DESC, topic_date DESC LIMIT 10