Thanks helpful friends.

Well, my burner is only 8x to start with, but I think I'll try slowing it down to 4x and see if that helps. As well as closing any other files that are running in the background. (Though how about createcd and directcd ?)

Since I've only got one CD drive, Adaptec copies the tracks to a file on the hard drive anyway. I suppose I could copy to an ordinary file myself, and load it across "by hand", but would that be any more likely to avoid the problem.