MANY thanks for the replies. Further investigations reveal that it's not the media (the disks).
I phoned the printers, who said that always happens at their end - they put our burned disk in and get no contents - they are now in the habit of putting it straight into an external drive (an LG DVD writer/reader) and proceed from there. They also commented that we are not the only customer with whom this happens.
What brand of blank CDs are you using?
There is a BIG difference between different brands of blanks! Every manufacturer uses their own custom, proprietary organic dyes in their blank CDs. I have encountered many brands of blanks, most notably Memorex blanks, that can not be read on standard CD-ROM players, only on some brands of burners. (Memorex blanks are so unreliable, I once had someone offer me a case of them
for free and I said no.)
