Score queries seems to be problem as they consume too much CPU.
Ex:
SELECT target.post_id, sum(target.weight * log(6935 / least(6935, freqs.freq))) as score
top indicates that mysqld reaches almost ~300% of %CPU with the plugin activated while visiting posts on a WordPress v3.6.1 installation and WP Related Posts v2.9 plugin.
HTH.
Greetings.
It seems like it is looking for the feed module, the offending code on plugin.php is:
if (is_file(WP_CONTENT_DIR . '/extensions/newsletter/feed/feed.php')) {
require_once WP_CONTENT_DIR . '/extensions/newsletter/feed/feed.php';
} else {
require_once NEWSLETTER_DIR . '/feed/feed.php';
}
Given this logic, users who do not have this extension won’t be able to activate the plugin.
