Mark:
It's a psd file with no alpha channel. It's grayscale so the only channel in Photoshop is gray. But it is on a transparent background and only one layer.
I did what you suggested in Motion but in the Media tab in the Utility pane, it doesn't matter how I toggle the value, the "white background" in the canvas still appears. My canvas preference is transparent, however white fills in the balance of the grayscale image.
Thanks for your assistance. I'm happy to follow any other suggestion.
Jamie