I'm experiencing annoying bugs with the new interface. Often clicking triggers a very different effect than what I expect. It's almost as if a shadow drawer would be present, completely transparent. I often end up using a potion when I want to click "go" to ascend/descend via stairs. I use 1x windowed mode.
EDIT: Case in point:

I clicked a *mana potion*. Why does my character attack Blah-blah? I dig the Citizen Kane reference but I'm *not okay* with having to restart a vicious map just because DD assumes that by clicking the Mana Potion I really intended to attack the boss. It's not fun.

"Thinker", just without the "ache".