[Plugin: Yet Another Related Posts Plugin] MySQL error on every query

I just installed YARPP. A great plugin, except that I’m noticing my error logs full of MySQL errors.
I’m running WP 2.91, YARPP 3.1.3 and my server runs MySQL 5.1.3.

I have even tried deactivating and reactivating the plugin and dropping the YARPP cache tables. Didn’t solve the problem.

Examples of the errors:
—?[30-Jan-2010 21:21:04] 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 set names made by require, require_once, include, related_posts, yarpp_related, yarpp_cache_enforce, yarpp_cache_keywords
and
[30-Jan-2010 16:17:02] 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 set names made by include, do_meta_boxes, call_user_func, yarpp_metabox, yarpp_related, yarpp_cache_enforce, yarpp_cache_keywords

URL example:
https://www.uncorneredmarket.com/2010/01/10-tips-for-taking-great-food-photos/