When I import the clips onto the timeline, a yellow bar is displayed, indicating an incompatibility with the sequence/project settings. The sequence settings seem to match. The only relevant project property I am aware of is Capture Format, which I have set to DV. (The only choices are DV and HDV.) However, despite the yellow line, the video plays properly in the Program Monitor.
No, that's not correct. The yellow bar simply indicates that Premiere may or may not be able to playback the sequence in realtime with the footage it currently contains. When it comes time to export, the frames in those clips will be rendered, regardless of whether they contain any effects or transformations.
Capture format has no implication in your case, unless you're planning on capturing DV or HDV.
When I render, I get a green bar, but the preview window now displays the video sqashed to the left, as if it is trying to display 720 pixels of width. The video plays smoothly and the sound is OK. When I export (e.g., to AVI), the video displays properly - it is not squashed.
Don't render; there's no need to. If you must render, make sure your sequence is not set to use DV as the preview codec. You can't--at least, not with the sequence settings you're using. DV is a fixed standard that can only exist as 720x480 with a PAR of .9091 (for NTSC). When you try to render your 320x240 sequence as DV, the encoder is forcing your non-standard (for DV) dimensions into standard DV dimensions. No good can come of it. For a preview codec, try something else; either a different AVI codec, or use the MPEG I-frame option.
So the problem appears to be with the Program Monitor window. I have checked playback settings, and not much there seems to relate to AR. There is a choice for AR conversion- I have tried all three choices (None, HW, SW) and no choice makes a difference. I have no external device connected to the system.
Nope; the problem is the preview codec. The playback settings won't help you; neither will the aspect ratio options.
One would think that if the source clip is 320x240 and the sequence is 320x240, the program monitor would display 320x240 rather than 720x240, which is what it looks like it is doing.
If you change the preview codec as instructed above, you should not see any change in the rendered output, either in frame size or aspect ratio.
I have a QT file 720x480. When I drop it into Media encoder it sees the source size as 853x480. In QT inspector it sees it as 720x480. What's the deal?
It's a widescreen video, with a PAR (pixel aspect ratio) of 1.212. Does it look squished in QT Player, but correct in AME?
PS: you might want to start a new thread, if this information doesn't help.