The files read off the disk fine; I copied them onto a harddrive without any problem and unchecked the read-only tag; I extracted all the files using isobuster to the harddisk and they don't have the readonly tage set when this is done.
It has only affected the adobe files on the disk. Gifs and jpegs are fine but illustrator, acrobat & photoshop won't read the files at all.
this is the illustrator dialog which pops up when trying to open the file.
and then it hangs.
so there must be something in the encoding which is tricking Illustrator.
There was nothing different about this CD to the other 6 I burnt and they all work fine.