I tried to copy a movie from a copy. It doesn't work but the copying process stops "errors". I used clonedvd, alcohol120, nero6. My burner is a Toshiba SD-R 6372 Firmware Rev 1030 (good for dvd+-R at 8x).Thanks.
The disc is probably damaged, could be on purpose to stop a copy or by accident. You'll have to rip this one, use DVD Decrypter.
If you used Shrink, you'd have a temp file that you could use over again.