dsn- The problem is not with the DVD's/ CD's, your problem was the way you went about it. You should of saved the project (the editing process of the video you were making). You burned the end product on DVD and then when you redid it, you redid the end product and not the editing process. If you saved the edited process, you would of just had to open it up again and make any changes and then burn the new end process. It would have to be on a new DVD mind you as once a DVD is burned, it cannot be reburnt, unless it is a DVDRW (re-writable). Hope that was clear enough to understand.