Did you use the key with a newly installed zemana? I see you didn't download zemana from the link they give you on the email (it's an older version).I used it to activate the latest version 1.9.2.507, works fine http://cdn.avinashtech.net/images/smilies/smile.png
I'm looking at my currently active license -If I remember correctly it's from a facebook promo- and it's longer and very different from the one I received with this promo.
By the way I have the same product version, 1.9.2.507 and heuristics kernel module 1.9.2.501.