Installed plugin, put <?php related_pages(); ?> into my custom template, and I always get "no related posts". I set Threshold to 1 and same results.
A couple weird things: I cannot change titles and bodies option from "do not consider" they are grayed out. When I first installed it asked me to change to the MyISAM engine... which I did.
I have also deleted and reinstalled the plugin to no avail.