Actually, it is an oversight. You can still press the key, get the 'Ouch!', and (still holding the key), press the mouse button to get the desired effect.
I forgot that some people use the Ctrl/Option/Apple keys to simulate mouse presses. I'll remove this change sometime next week.
Also, if you are using a Mac:
buy a 3 button mouse!. They are cheap and it makes using AFNI much more pleasant.