Hi Stefano,

In order for related post feature to work, you need to associate some tags on your blog post so that the system can relate each of the blog post based on the tags used. I've checked your blog post "Gigolo ospite al talk show di Vera TV" and it seems like the blog does not contain any tags inside, http://screencast.com/t/LNNCrHyyc hence the related post will not shown.

Hope these help.