After investigating issues with the database I saw that the error_log file in the public_html directory was being filled with errors like this:
[10-May-2012 02:30:48] 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 p.post_date DESC LIMIT 1’ at line 1 for query SELECT p.* FROM wp_posts AS p INNER JOIN wp_term_relationships AS tr ON p.ID = tr.object_id INNER JOIN wp_term_taxonomy tt ON tr.term_taxonomy_id = tt.term_taxonomy_id WHERE p.post_date < ‘2012-05-07 14:45:00’ AND p.post_type = ‘page’ AND p.post_status = ‘publish’ AND tt.taxonomy = ‘category’ AND tt.term_id IN () ORDER BY p.post_date DESC LIMIT 1 made by require, require_once, include, get_header, locate_template, load_template, require_once, wp_head, do_action, call_user_func_array, adjacent_posts_rel_link_wp_head, adjacent_posts_rel_link, get_adjacent_post_rel_link, get_adjacent_post
[10-May-2012 02:30:48] 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 p.post_date ASC LIMIT 1’ at line 1 for query SELECT p.* FROM wp_posts AS p INNER JOIN wp_term_relationships AS tr ON p.ID = tr.object_id INNER JOIN wp_term_taxonomy tt ON tr.term_taxonomy_id = tt.term_taxonomy_id WHERE p.post_date > ‘2012-05-07 14:45:00’ AND p.post_type = ‘page’ AND p.post_status = ‘publish’ AND tt.taxonomy = ‘category’ AND tt.term_id IN () ORDER BY p.post_date ASC LIMIT 1 made by require, require_once, include, get_header, locate_template, load_template, require_once, wp_head, do_action, call_user_func_array, adjacent_posts_rel_link_wp_head, adjacent_posts_rel_link, get_adjacent_post_rel_link, get_adjacent_post
Upon further investigation I discovered these errors were being caused by the “minimu” plugin installed. After disabling this plugin these errors no longer appeared in the error_log file.
