[Plugin: Search Everything] SQL Error in Search Everything

I am experiencing some odd SQL errors from the search everything plugin. With WP_DEBUG turned on I get the following message:

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 wp_posts.post_type IN ('product') AND (wp_posts.post_status = 'publish'' at line 5]
SELECT SQL_CALC_FOUND_ROWS wp_posts.* FROM wp_posts WHERE 1=1 AND ( wp_posts.ID NOT IN ( SELECT object_id FROM wp_term_relationships WHERE term_taxonomy_id IN (60) ) ) AND ((())) AND wp_posts.post_type IN ('product') AND (wp_posts.post_status = 'publish') GROUP BY wp_posts.ID ORDER BY wp_posts.post_date DESC LIMIT 0, 10

The SQL query is obviously being modified by search everything and the problem looks to be around AND ((())) AND which certainly does not look like a valid SQL query.

I am using custom post types and taxonomies and have search ‘all taxonomies’, ‘categories’ and ‘authors’ enabled in the search everything settings.

Any pointers would be greatly appreciated.

http://ww.wp.xz.cn/extend/plugins/search-everything/