It's not DVGrab or Kino that is 'striping' the video. It's interlaced. You can feed it through mencoder to deint or any other deinterlacing application, but that's probably what the "striping" you are seeing is.
In the simpliest way possible of imaging it, dvgrab is just grabbing the 1's and 0's from your tape and structuring them with a file that is usable on a computer (for editing I'd suppose), so it's not doing anything that your camera didn't already do
Cool