I make videos on a quad-core Mac Pro vintage 2008 using iMovie and iDVD, OS 10.5.8. I use DVD+R discs which work fine in all my DVD players hooked to my TVs. They play fine in other Mac Pros, iMacs but for so reason it will not be recognized by my 13" Mac Book Pro vintage 2009, OS 10.5.8. Gives me a message about what to do with blank DVD on insertion. This has me stumped, what can be done if anything so that I can view said discs.