Backing up the OS X final CD?



I received my copy of OS X final today like many people. I decided to make back-up copies of all three CDs in case anything should happen to the originals. The OS 9.1, and Developer Tools CDs copy just fine. However, I have been unable to copy the OS X final CD. I attempted this two times, both times during verification I get a byte mismatch error. Is this the result of some form of copy protection? Is there a method to successfully back-up this CD? Thanks for any help.