I've captured my 16:9 footage with the capture presets as: DV NTSC 48KHZ Anamorphic. I've noticed the problem after burning it to DVD. If I "print back" to video, the video is sharp. When I export to Quicktime for DVD, I use Quicktime Movie export selection, and keep it selected as "current setting", and then import. That's the file I use to burn to DVD. I've been using IDVD to do the burning, since it's the quicker program to use instead of DVD Studio Pro.
Joe