Finally I figured out myself, what was wrong with my Facebook comments plugin settings. Maybe some of you are facing the same problem and still don’t know how to solve it.
So, all you have to do is to go to plugin settings/comment box settings/number of post to display. Insert some number there – e.g. 100.
That’s it.
My plug in finally works perfectly. Even the function “Notify me about Facebook comments by email”, which didn’t work before, now is doing its job.
Yeyyyy!!!!