Selecting built-in captcha for DocManager, Joomla, K2 and EasyBlog articles as opposed to ReCaptcha caused my site to get to produce way too many slow SQL queries, making my site inoperable, producing lots of blank pages, especially after logging in or trying to open a bigger Joomla document. The slow SQL queries are referring to Kommento and Captcha. Unfortunately, after switching from built-in captcha to ReCaptcha the problems continue, leaving my 6000 - 15000 daily visitors very upset.