Sitemap Problems

I am getting this problem when I activated my dd-sitemap-gen plugin. Any suggestions on how to fix this??

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 ‘AND comment_approved = ‘1” at line 3]
SELECT COUNT(1) FROM wp_comments WHERE comment_post_ID = AND comment_approved = ‘1’