Motion 5 is hanging with the simplest emitter effects (qtkitserver)

On both my retina MBP and new Mac Pro (6 core d500) I am finding Motion unusable. Just a simple effect (like any of the emitters) is very unstable. Activity monitor shows qtkitserver stops responding. Motion gets extremely laggy....beachballs....long freezes.

The Mac Pro is a super clean install. Anyone have any ideas? Thanks for any help.

Kevin