The premium site has the "Built Deck" feature, where cards are counted as "in use" in your inventory. Normally, when you're building a deck and list more copies of a card than you have available, there's a red shading that alerts you to the fact you don't have enough cards. But if, say, I have only one copy of a card, and try to use it in two different decks--even if one or both are marked as "Built"--I never get the warning. This happens regardless of whether or not I have "I am sharing cards between built decks" checked in my settings. I find this really obnoxious as I'd love to be able to use the site to e.g. plan what singletons go into what deck or cube.
Is this a bug? Or am I doing something wrong?