SQL error in my site error log

I just checked my error logs and found the following message (multiple times):

[Fri Apr 12 11:15:36 2013] [error] [client 96.126.117.155] 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 ‘) ORDER BY ad_id DESC /* From [soaringcafe.com/wp-cron.php?doing_wp_cron=136576’ at line 1 for query SELECT * FROM wp_awpcp_ads WHERE ad_id IN () ORDER BY ad_id DESC /* From [soaringcafe.com/wp-cron.php?doing_wp_cron=1365765336.1186931133270263671875] in [/nas/wp/www/cluster-1084/soaringcafe/wp-content/plugins/another-wordpress-classifieds-plugin/classes/models/ad.php:116] */ made by do_action_ref_array, call_user_func_array, doadexpirations, AWPCP_Ad::find

Does this need to be fixed? And, is there something I need to do to fix it?

Thanks,
Bill

http://wordpress.org/extend/plugins/adrotate/