I just bought this Pioneer DV220KV DVD player...it will only play about 50% of the MP3 files I have on DVD-R's...it doesn't recognise the others. They don't show in the Menu etc. Every file was burnt to the discs in exactly the same way. Every file always plays perfectly in my computer's DVD drive and on every other old player I have here. Any ideas? I like the sound of this Pioneer,but if it won't recognise half of my music,then it will have to go back.