Not having experience with the Pioneer machines, I need to ask this question: Are you sure that your Pioneer is really a "CD/RW-DVD/RW" machine? Or, could it be only a "CD/RW-DVD/R"? If it isn't a full CD/RW-DVD/RW, you will only be able to read DVDs, not write them. Also, for what it's worth, I have been told to only use DVD-R blanks and not use DVD+R in my G4. I have no reasoning behind that instruction, only the word of a friend who said that the +R blanks won't work well with my Mac.