Thanks for your response, I really appreciate it!
We have been doing this, but it seems to be squashing the video.
I thought the 720 x 540 square pixels translated to same size and aspect ratio as 720×480 rectangular pixels. If so I should not be having to resize it /make it alter to fit the comp.
It is important for the content we are making that nothing gets squashed as they are educational and a circle must be a circle, not an oval, etc.
Thanks again!
June