Duo2 recognizes PSX backups as Audio CD's?
 

Had the Duo2 for about 9 months in my V6 Ps2. It plays original PSX fine. I have played these same backups fore the whole time I have had the Duo2. It boots Ps2 titles on same CD Media:Imation(and some others, but I have used these primarily) It goes to the CD Player menu.