Subscribe by Email plugin Error

I get this kind of error. How to fix?
[16-Nov-2013 15:11:02 UTC] WordPress database error 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 ')' at line 1 for query DELETE FROM wp_253_subscriptions_log_table WHERE id IN () made by require_once('wp-load.php'), require_once('wp-config.php'), require_once('wp-settings.php'), do_action('init'), call_user_func_array, Incsub_Subscribe_By_Email->maybe_delete_logs, Incsub_Subscribe_By_Email_Model->delete_log