Signup status log show significant warnning

I just newly install a fresh copy of Drupal 6.13 and related signup modules. When I view the 'Signup status log' page, I see:

user warning: Column 'mail' in field list is ambiguous query: SELECT signup_status_log.lid AS lid, signup_status_log.timestamp AS signup_status_log_timestamp, node_signup_status_log.title AS node_signup_status_log_title, node_signup_status_log.nid AS node_signup_status_log_nid, users_signup_status_log.name AS users_signup_status_log_name, users_signup_status_log.uid AS users_signup_status_log_uid, signup_status_log.uid AS signup_status_log_uid, signup_status_log.anon_mail AS signup_status_log_anon_mail, mail, users_signup_status_log_1.name AS users_signup_status_log_1_name, users_signup_status_log_1.uid AS users_signup_status_log_1_uid, signup_status_log.cid AS signup_status_log_cid, signup_status_log.action AS signup_status_log_action, signup_log_signup_status_log.nid AS signup_log_signup_status_log_nid, signup_log_signup_status_log.sid AS signup_log_signup_status_log_sid, signup_log_signup_status_log.uid AS signup_log_signup_status_log_uid FROM signup_status_log signup_status_log LEFT JOIN signup_log signup_log_signup_status_log ON signup_status_log.sid = signup_log_signup_status_log.sid INNER JOIN node node_signup_status_log ON signup_status_log.nid = node_signup_status_log.nid LEFT JOIN users users_signup_status_log ON signup_status_log.uid = users_signup_status_log.uid LEFT JOIN users users_signup_status_log_1 ON signup_status_log.admin_uid = users_signup_status_log_1.uid ORDER BY signup_status_log_timestamp DESC LIMIT 0, 50 in E:\Inetpub\wwwroot\drupal_events\sites\default\modules\views\includes\view.inc on line 755.