Unknown column 'm.user_name'

Every time I navigate in Mugshot gallery:

user warning: Unknown column 'm.user_name' in 'field list' query: SELECT m.mid, m.path, m.timestamp, m.visible, u.uid, u.name AS registered_name, m.sid, m.user_name FROM mugshot m INNER JOIN users u ON m.uid = u.uid WHERE m.preview = 0 ORDER BY m.timestamp DESC LIMIT 0, 24 in /home/ymessro/public_html/includes/database.mysql.inc on line 167.

I can take images from my web camera but they don't appear anywhere.