Have you verified the checksum of your downloaded iso files?
Did you burn the cd/dvd as slow as possible?
Did you verify the content on the cds?
I used K3D to burn the disk, Burn speed 8x, With K3D I do a simulation first that was ok, on the second burn I burned and did a verify after, that's when it comes up with the fault 75% through verifying the data, the question remains has anyone had the same problem? I can expect one to fail but not two, with the same error