Mets1fan

I am very new at this, so I apologize if what I'm saying sounds stupid. I'm trying to change the Book Type of my DVD+R drive to DVD-Rom, so that I can play the DVDs in a DVD Player that will not take DVD+R/RW. I have an NEC ND-1100A, with firmware 1.93. When I go to the change book type screen and NEC tab, no matter what choice from the pulldown I make, it says "Unknown (FAILED!)" and I can't change the booktype. Is there any way of making this work? Am I doing it wrong? Thanks in advance.