Hi, I'm asking this question again as I had no response the first time. I know from reading that it's been a common problem, but after applying the recommended fix, the problem remains. An abbreviated error message is below, I have replaced wp-includes/wp-db.php with a freshly downloaded version but nothing has changed. I would really appreciate some help with this please.
(I'm running 1.5.2)
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 post_status = 'publish' AND post_date <]
UPDATE wp_posts SET comment_status = 'closed', ping_status = 'closed' WHERE (comment_status = 'open' OR ping_status = 'open')' AND post_status = 'publish' AND post_date < '2006-01-03'
Warning: Cannot modify header information - headers already sent by (output started at /var/www/html/blog/wp-includes/wp-db.php:98) in /var/www/html/blog/wp-comments-post.php on line 51