Hey AceGambit, just to say, the reason why the deck you bought from the JAQK website is a two way back is because they've run out of stock of the original decks. So, they sell the Theory11 decks straight from their website. You can partly tell that anyway, seeing as the deck you have doesn't have a seal.
Also, just to back up my point, when I emailed JAQK to ask if they had any JAQK decks left in stock, part of the reply said "Yes, we do have our second edition playing cards in stock.". So, they no longer stock the first edition ones that they themselves made, but they stock the second edition ones made by Theory11 instead.
Hope this clears up any confusion.