From Wikipedia:
Gracenote, Inc., formerly called CDDB (Compact Disc Data Base), is a company that maintains and licenses an Internet-accessible database containing information about the contents of audio compact discs and vinyl records. It provides software and metadata to businesses that enable their customers to manage and search digital media. Gracenote provides its media management technology and global media database of digital entertainment information to the mobile, automobile, portable, home, and PC markets. Several computer software applications that are capable of playing CDs, such as Winamp, Media Go, and iTunes, use Gracenote's CDDB technology. Gracenote’s database was originally created from and continues to receive voluntary contributions from users. This led to a licensing controversy when Gracenote became commercialized.

It is used on the Penbex devices. When you insert a CD, the device checks gracenote for track information which it then displays.
So it is possible that when you play a CD that does not contain any track information at all, you can still see the name of the artist(s) song and album on your lcd screen.

BR,William

They only supply details if a cd is in their database.
So the most logical explanation would be that the CD's you play are not in it.