Can't read Zwan CD in 40125S

Refuses to even detect the CD insertion. I have a Liteon 166S DVD-rom and it works fine in that. I have tried other CDs in the 40125S and they play fine. The CD is brand new, unmarked. My 40125S is running latest ZS0P firmware.

And before you ask, yes I am using the Zwan CD and not the Zwan DVD

Any ideas ?