True...it would identify the problem. Also, if you are using DVDShrink just be aware that the program hasn't been updated for a while so there might be new CSS copy encryption that will beat it. Try DVD Fab decrypter instead...get it here:
If you use FAB, be aware that it only decrypts. You'll still need to use Shrink to shrink the DVD to fit on a dvdr-.
Hope this helps.