Just fooling around with this plugin in my test site. I installed the latest version, activated the plugin, ran the check, all worked fine. Then my eye fell on the suggestion to change the wp_ suffix for tables, so I gave it ago and changed them to tst_. The report said that all changes were successfull except two wpau_ plugin tables which I had to change manually. So when I decided to see if the site was still up, I got the screen that I had to install WP and then I got a password. Very funny! So now the site is a completely fresh and new WP installation without theme, posts or anything.
That wouldn't have been funny if it was a live site!