No Video Preview Image in Settings - Can't see Source or Output! (CS5 / Mac Lion)

This program has been working fine for me until I got a new computer.
Opened up CS5 and dragged in my video files to convert -- and when I click "Settings...", there SHOULD be a video image preview for both my source and output.

However, this preview is gone.
If I actually start the queue, I can see a preview image in the queue window, but not in the settings window.

Need to have this preview image so I can mark in/out points accurately, but I just can't get it to show up.
Tried all types of video files, and nothing is displaying.

Could this be an issue with Mac Lion?
Was working fine with Snow Leopard...

Any ideas? Thank you!

Thanks for the link. Good to know.