MPEG-2 results in 720x404 - not 853x480?

There was a thread about this earlier, but it didn't answer my question and was marked as answered, so I thought a new thread would be best.

Here is my situation. I have a QuickTime export from Final Cut Pro that is going into Compressor to generate my MPEG-2 for the DVD it's going on. The resolution of FCP QT file is 720x480 and the aspect ratio is 16x9. And in QuickTime, when I Get Info on the file it says it is 720x480 (853x480) which, from everything I know, is anamorphic 16x9. From all of the MPEG-2 and DV files I've worked with 853x480 has been the resolution I've seen anamorphic 16x9 be.

However, after Compressor is done exporting the MPEG-2 of this file, it is 720x404. While that is a 16x9 (well, one of the various versions anyway) aspect ratio, it seems like somewhere along the way the image is either being cropped or scaled down from the original instead of preserving the original size.

Does anyone know why Compressor would give me a 720x404 16x9 MPEG-2 instead of a 720x480 (853x480) anamorphic 16x9 file?

Hope that makes sense.

-Michael