Error on Cron: You have an error in your SQL syntax

Hi,

when cron runs I see the following error message on the database log entries list:

	You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ') GROUP BY t1.uid, t1.uaid HAVING COUNT(t2.uid) <= 10 ORDER BY t1.ui' at line 11 query: SELECT t1.uid, t1.uaid as 'uaid', COUNT(*) as 'rows_per_user', t1.timestamp as 'real_date', MIN(t2.timestamp) as 'oldest_date', count(t2.uid) AS 'count' FROM heartbeat_activity AS t1 INNER JOIN heartbeat_activity AS t2 ON t1.uid = t2.uid AND t2.timestamp >= t1.timestamp WHERE (t1.timestamp, t1.uaid) < (t2.timestamp, t2.uaid) AND t1.message_id NOT IN () GROUP BY t1.uid, t1.uaid HAVING COUNT(t2.uid) <= 10 ORDER BY t1.uid, t1.uaid, t1.timestamp DESC in /var/www/vhosts/project.com/httpdocs/sites/all/modules/heartbeat/heartbeat.module in Zeile 483.

Additionally at the same time the following two error messages are listed - maybe they are connected to the above?!

	implode(): Invalid arguments passed in /var/www/vhosts/project.com/httpdocs/includes/database.inc in Zeile 253.

and

array_fill(): Number of elements must be positive in /var/www/vhosts/project-com/httpdocs/includes/database.inc in Zeile 253.

Best,
Tobias