That's a bug. Both that achievement and "The Sorcerer's Apprentice" have errors in their Game Center data preventing them from working with the current build. We have a fix that will be released with our next update.
That'll definitely be on our end. Check in the Network tab of the Options menu in the game to make sure you're still logged in to your Hidden Achievement account. We're working on fixing a bug that's currently causing the game to check in every time you run so those will be available for offline play.
@dc4u2 That's not a "confirmation" window, per se. It's there to notify people (including other players, in a network game) that the event happened. Jason has advocated for having an optional verify dialog for discards, for people who want that (especially when they're just starting out and might hit that button by accident), and we do have a work ticket in our system for that, but it didn't make the cut for this particular version. Your request, however, will influence how we prioritize this for future patches. Thanks for the feedback!