If I try to quickly put down two of an item into the crafting grid (using the right mouse button), only one click is registered. This completely ruins the flow of crafting. Similarly, if I try to lay down a whole stack with a left click, and then immediately pick half of it up again with a right click, the second click isn't registered, and the whole stack is left. A final "sibling" of this bug occurs when trying to double click to pick up all instances of the held item from an inventory, such as when multiple small stacks of a stick is lying around in random places.