Just a minor bug. Obscure stone does not stack in my inventory when i sort on arcane item from the menu, but only when sorting on Cost, Rarity or Level. It's the same in both the keep and shop. The two i have seem identical in every way. I have gone out and logged back in three times, nothing changed. Edit: Weird, after playing an adventure i checked again, and they stack normally now.
Is it on the right-hand side of the inventory box? I've noticed a couple items doing that intermittently and couldn't reproduce it until today when I realized that the second item would probably go out of bounds if it were stacked under the first one.
Yes, you are right. I won a new arcane item after playing that adventure. And it moved the Obscure stone to a new position. After removing an item i could reproduce the old situation.