As others have said, the issue is that animations can only be triggered
by clicks, not mouse overs. However, there are other actions that can be
triggered by mouse over. These include hyperlinks and VBA macros. A
simple mouse over animation effect is easy to fake by hyperlinking to
another slide. The other slide would be identical, except that it has an
automatic animation set that happens immediately that does whatever you
wanted the mouse over animation to do. This is very easy with one mouse
over animation on a slide. The difficulty comes up when you want to do
this two or three or more times for a single slide. The number of
combinations grows exponentially (e.g., what happens if I mouse-overed
one but not two already; is the slide going to look different than if I
mouse-overed one and two but not three?).
--David
