I have a DVD of a Dance Concert, provided by a professional video guy.
Recorded in PAL MPEG Audio Standard.
I've attempted to copy DVD using Nero Express 6, both by Save & Burn, and Copy & Burn. My burner is TSSTcorp CD/DVDW SH-W162Z (DVD).
Result: On copy, I can select the first three items. After that, I can't skip, ffwd, select or anything but 'playthrough'.
The original does all it should do.