Are you telling the CD burner to do what you really want? I also produced a number of coasters using K3b until it was pointed out to me that one MUST tell K3b to BURN and not merely to copy or write to CD. As soon as I started to BURN CDs, the ISO images were burnt correctly onto the CD and I could boot from the CD so produced. Incidentally, I needed to do this as I have a DVD burner on my system but only a CD reader on the other system on which I wanted to install Fedora FC4. CroombeFP
