Spam comments in error.log?

Okay, this is a weird one and it’s got me completely flummoxed. I’m seeing spam comments being entered in my WP root error.log. Around the same time I also started seeing errors like this:

[26-Jan-2008 15:06:51] 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’ ORDER BY comment_date_gmt DESC LIMIT 5′ at line 1 for query SELECT wp_comments.* FROM wp_comments WHERE comment_post_ID = AND comment_approved = ‘1’ ORDER BY comment_date_gmt DESC LIMIT 5

This all started happening about the time I upgraded to the latest version of Akismet but I have no way to tell if this is actually the problem or not. I suppose I could switch over to Defensio just to check to see if that stopped this from happening but I wanted to throw it out to the community first to see if anyone has ever seen this before. I know I haven’t.

I’m running 2.3.2 on PHP 5.2.5, SQL 5.0.45

This is usually a clean running install and has been for close to two years now but this has got me stumped. The database tables are “OK” when checked and I optimize once a week.

Any help?