You did not state that you had tried to read other Data CD's in your CD/DVD reader.

Have you been able to read other CD's in that drive?
Have you been able to read the True Scale CD in a drive on another PC?

Do you have more than one CD Reader? If so, have you tried the other CD Reader?

Have you rebooted since you tried to read the True Scale CD? If not, please do it and try to read the True Scale CD again.