Dear developers, the cards switch in deck, after you finished editing the deck, I think that's what "theevilpenny" meant. It's not a bug or whatsoever, but personally, I like my cards in rarity order and it doesn't keep it at that position, so when I'm editing it again, they're like in a random position, not where I put 'em.
 "Berserk: The Cataclysm"){kind=icon}
 "Wasted Youth, Part 1"){kind=icon}