SQL Statement Bug in Remindme.module

While running cron.php,

> wget -O - -q http://dev2.edutech.mu/cron.php

remindme.module generates error:

user error: Unknown column 'u.nid' in 'group statement'
query: SELECT r.nid, r.timestamp, u.uid, u.name, u.mail, n.* FROM remindme_node
r INNER JOIN node n ON r.nid = n.nid INNER JOIN users u ON n.uid = u.uid WHERE n
.status = 0 AND r.timestamp > 0 AND 1072761541 + r.timestamp > 1072858688
GROUP BY u.nid, n.nid in /home/www/dev2.edutech.mu/includes/database.mysql.inc o
n line 90.