Ok. Yeah, I suspect it's not necessary to also install the x32 version on Mac to use QT, so that may be normal. Sorry, I know that doesn't help you with your current problem.
Hopefully somebody who knows more about this will pop in to help.
Exporting with Alpha Channel Legacy Quicktime
Moderators: Víctor Paredes, Belgarath, slowtiger
Re: Exporting with Alpha Channel Legacy Quicktime
Animations, Tutorials, and Cats (Oh, My!) Little Green Dog Channel on YouTube!
D.R. Greenlaw
Artist/Partner - Little Green Dog
Little Green Dog Channel | Greenlaw's Demo Reel Channel
D.R. Greenlaw
Artist/Partner - Little Green Dog
Little Green Dog Channel | Greenlaw's Demo Reel Channel