Usually playback problems are due to a bad burn.
What mediacode have these media exactly? You can retrieve mediacode with cd-dvd speed. What burner do you have? What speed did you burn these media exactly? If you burned a 16x media @4x, is higly probable (not absolutely sure, but higly probable) that you obtained a bad burn.
Moreover, some standalones are really picky with media. To improve compatibility is a good idea to burn +R media setting booktype as ROM.