Through v8, Virtual CD could create audio CDs that stored tracks as sound files (such as MP3 files). With Windows Vista and later, CD drives can no longer be switched to analog mode. Analog mode is required for playing virtual audio CDs that have tracks stored as sound files, as opposed to normal data files. This explains why some CDs cannot be played if you are running Windows Vista or later.
For the same reason, Virtual CD version 9 and later cannot create this type of image. However, you can still create 1-to-1 images of audio CDs, and play them, with Virtual CD.