Well, I got it to work, although I'm a bit mystified as to how. Basically I took the 720x540xsquare images, resized them to 720x480xsquare in photoshop (redoing them using the NTSC setting in photoshop would have been too huge a task, since the image size function doesn't seem to allow for changing the pixel aspect ratio), then brought those into premiere and saved my avi to 720x480x0.9pixel aspect, and the results on my TV look good to me. Maybe they are slightly distorted but not enough to be obvious, or maybe premiere somehow did the proper thing to the images, either way, the results will do. Thanks for your help.

- Neil