Keynote Presentation Troubleshooting - Image on Slide - "Action" Animation Build Order - Start with After Transition Selected but Animation only starts with Mouse Click.

The "Action" animation is a simple scaling of an image from 100% to 120%. A single animation on the slide. What is strange is that the previews of the two size extremes of the image at 100% and 120% disappear when going back and forth to previous or next slides. When I go to present I have to always Click Mouse for transition to the slide, and then click mouse again to activate the animation even though the build order selection is set to "After Transition."

Latest version of Keynote downloaded so not an update issue.

Help!