Thanks Jet - I have it :-)
It looks as though there is a slight error on the authoring of the disk, which is stopping it from reading properly, even though it plays well on the PC. Believe it or not, the basic CDRW/DVD prog Roxio 6 can import vob or inf files from disk. I have had this program for a long time, but never thought about using it this way before. Sadly, it still doesn't work on this job! :-)
Conan