How to get rid of automatic related posts? Help!

Hi, and thanks for the wonderful theme!

I’ve got a problem. I have a great Related Posts plugin installed, and I’m completely satisfied with it. However, recently I discovered that out of nowhere, a second “related posts” thingy appeared, which seems to be encoded somewhere and I simply can’t get rid of it. The settings for it are in Settings-Reading, but there’s no option to disable it whatsoever! It’s really annoying. Here are screenshots of what it looks like:

http://i.imgur.com/a7J8keh.png (here it shows at the bottom, all I could do was remove the name “Related”)
http://i.imgur.com/sAKokeZ.png

Is there anything I could do to remove it?
Thank you in advance!

Btw, that trick to remove the tags (when you add a code line in the style.css) won’t work for me either =(

Best,
Kira