This is a quick method to backup a DVD with AC3 sound on the Sony DRU500a using the included version of MyDVD. First rip the disk to your hard drive and tell whatever program that you are using ONLY to include the original video file and the AC3 audio file in a VOB file. Make sure this VOB file is a single chunk to take up one recordable DVD or two VOB files for two recordable DVDs if the movie is long. Once you have your 1 or 2 VOB files then rename their extension to .mpg from .vob. Now open MyDVD and add the file, author and burn. Repeat for the second half if necessary. This method has worked well for me, but tends to use more disks. On the plus side, I don't have to do all the encoding now and retain all the original movie quality. I am not sure why it works, but it does. I have not tried anything more advanced than this and probably won't.