Chartbuster Cd's Won't Copy For Back Up???

[hogwild]

I have 2 ESSENTIAL +PLUS Chartbuster cd's that won't copy or even play in my burner. They are from a 6 Disk Pack series Chartbuster ESP452-02 and ESP452-06. The other ones from this set copied fine but these 2 just die when I install them. They will work in my DVD player and CD +G player but not in the burner at all. I tryed to copy by duplicate disc and track by track but neither cd will work at all. I would like to back these up. What may cause this and what can I do to resolve it.
Thanks