Dup-DVD is very flakey - I've heard so many different experiences from people. I personally got it going ok but wasn't very happy with the results.
I now use DVD2SVCD which is a front-end that'll control all the other programs for you like BBMPEG, DVD2AVI and TMPGEnc etc. It installs all the other programs for you in the bundle except your encoding software like TMPGEnc (or CCE if you prefer to use this). The SVCD end results are the best I've ever seen.
Check out
www.vcdhelp.com for guides and links to the software.
Word of warning though, if you use TMPGEnc for encoding (thoroughly recommended) you only get about 30 days to encode MPEG2, after that you'll have to re-install or crack it.