This is a great plugin, and things are mostly working as expect. However, the related posts are being listed out of their order of relevance (and I suspect it is possible there are posts not being displayed that were more relevant).
Logged in as admin, it looks like this as an example:
- Debunking the Social Media Myth: A Framework For Social Media Strategies (14.65)
- 10 Rules For Driving Traffic Using Forums (1.401)
- Build a Media Channel with a Forum (5.778)
- Facebook is not a social network. No, really. (5.341)
As you can see, the second one has a lower rating than the third and fourth.