Double clicking and shift+clicking do nothing. Dragging a stack over empty slots to fill the empty slots works very, very slowly, and only distributes items one at a time. Pressing Q in the inventory while mousing over a stack does drop one item, but shift+q also drops only one item rather than the whole stack. Right-clicking a stack to distribute it evenly across the crafting table works to split a stack in half, but will not continue to distribute the stack evenly to any additional tiles.

Pressing shift+number to place items in the hotbar seems to be the only shortcut that works properly.

I have had these problems ever since the 1.5 update.