As far as I can tell, the term "sweded" does not mean "movie made from cardboard". I think it's just a cheap (read: crappy) recreation of a film. It seems as if this is a fairly new term that spawned from the movie Be Kind, Rewind. Is that correct?
Pretty much correct, which is why using the original audio keeps that one from actually being sweded, its just a cool recreation. Also, when making a sweded film, they should not watch the original movie again, they should just go from what they remember of the movie from when they watched it last, which can be years earlier. While that is not an actual rule to making a sweded movie, it's just what the creator of "Be Kind, Rewind", who originated the term "sweding", said about how one should make a sweded movie.
AtomSmasher - It makes it very confusing when regulars start changing their avatars! 
I originally created this avatar as a spray for team fortress 2, and since I had already done the work to create it, I decided to use it here as well
