I didn't post anything as I was testing different things... Here are the results:
1/ Spaceballs : at abour 2-3 hours after the begining, DVDFab Gold hit 100% but continued to work. At about 6 hours, I had enough and quit DVDFab. All this time was used for reading/compressing the DVD.
2/ A tried with Much a do about nothing (another Zone 1 DVD). This time, the reading/calculating/etc took 3 hours and the DVD was burned. BUT the DVD can't be read on my laptop (Zone 2) or on the home DVD player (dezoned). The .vob files can NOT be read on the computer either: I can hear the sound but no image and the sound jumps irregularly forward.
In both cases, the RCE setting was set to 1 as the DVD are zone 1. Nero 7 burn driver was used (via DVDFab Gold). FYI, the Zone 2 DVDs work OK. The DMA setting was checked OK.
Any ideas on what to test now?