Are you talking about making a copy of the copy? If that is what you want, I have done this several times and no problems.
Sometimes I've made copys from skipping and lego disc to make a good copy to play on my stand alone dvd player
When you copy a burned disc, all you're doing is ripping (reading) the disc. No more harm is done than if you had just played the disc. And the copy of the copy will be as good as the copy. That's why RIAA hates dvd backer-uppers.
