Pulled up the system requirements off amazon.com:
* Mac OS X v10.3.3 or later
* 867 MHz or faster PowerPC G4 or G5 processor
* 512 MB RAM (2 GB or more recommended)
* 10 GB of disk space for application, templates, and tutorial
* DVD drive for installation
* QuickTime 6.5 or later
* Display with 1024x768 resolution or higher (1280x1024 resolution recommended)
* One of the following graphics cards:
* NVIDIA GeForce FX 5200 Ultra
* ATI Mobility Radeon 9600
* ATI Radeon 9600 Pro
* ATI Radeon 9700 Pro
* ATI Radeon 9800 Pro
If it was designed for 10.3.3 and for a PowerPC processor you'll either have to try running Motion using Rosetta (enabled from the Get Info screen) or it just may be too outdated to use on your system if you're running Leopard. I know that certain Apple programs will not work or will quit unexpectedly like you're describing if you try to launch them on a newer system.