A friend showed me this easy way of copying a DVD to DVD+/-R:

1) Download DVDDecrypter (from www.doom9.org) and run it to create an .ISO image. The registered version let's you strip out French and so on to make the movie look better on the resulting DVD.
2) Download DaemonTools from www.daemon-tools.com and run it. Mount the .ISO image as a virtual DVD drive.
3) Use Pinnacle Instant DVD (or other copy S/W) to copy it to a DVD-R or DVD-RW.

It's quick, and easy! Finally...