Thanks for reading anyone/everyone, and I'm sorry if this thread is out of place. I recntly purchased a Sony DRU-720A DVD writable drive for writing DL disks. I had previously had a DVD+/-R/RW drive, so I'm not exactly a newbie, but anyway... my problem is this. I used the Nero software that came packaged with the drive and it works wonderfully; I've made four disks that all work just fine in my computer and on a few stand-alone units that I have tried. The problem is that three of the four I have made don't work on MY stand alone unit, which is a nice Panasonic all-in-one unit (a DVD player, 5.1 digital audio decoder, etc.). What I can't understand is that I used the same exact process four times --- same write speed, same type of discs (RiDatas, I had a five pack), etc. --- I didn't change a thing from one burn to the next --- but the first one I tried did not work in my player, the second one did work in my player, and the last two did not work in my player. They all work on my computer, they work on the older, cheaper players at my parents' house, so why do three of the four not work on mine? And why does one of them actually work? Any ideas?