Re: different sources - MPEG2 wide and dv 4:3

Yep, that's the look of interlaced footage, alright. The only time that "combing" happens is when there's movement of either the subject or the camera. You're seeing the 1/60th of a second difference between field 1 and field 2. You've got it right - computer displays are always progressive. Various programs will either display the video combed like this, throw away one field during playback, or interpolate between the fields.

Since you're working in DV, the only way to see true interlaced playback is to hook up a firewire camera or deck and play back through an external interlaced TV. Or burn a DVD, and watch on the TV.