If you use Motion 2.0 with Mac OS X 10.4 Tiger, you should update to Mac OS X 10.4.1 or later.
The Mac OS X 10.4.1 Update offers reliability improvements for float rendering in Motion 2 when used with an ATI graphics card. The update also addresses issues encountered when using some of the Core Image Unit filters provided with Tiger. Additionally, the update resolves an issue in which Motion could unexpectedly quit when using LiveFonts.