I often use Illustrator files in Motion. Most of the time I have no problem, but occasionally the Alpha dropdown in the Media tab in the Inspector is not present for a particular graphic. If I open the graphic in Photoshop and specifically create one and resave and reimport, still no luck. This has happened even when the parent graphic worked fine and I have made a sub-graphic, the sub-graphic will lose the ability to choose or use an alpha channel.
This is weird, because even .aif files give you this option. But on certain random graphics, the first parameter in the list is pixel aspect ratio rather than alpha type.
Anyone else ever see this, and more importantly, know how to fix it?