Very strange problem.
How large are the cd's you are trying to copy? And do you use 74, 80 or 90min cd's?
Try using clonecd, most new games are protected with somekind of protection. One of these protections makes the content of the cd bigger then it actually is, sometimes up to 5 gigabyte. If this is the case, I'm not sure whether Diskjuggler can copy it correctly.