Audio Issues with Amazon DVD's

Q? -- Have you had any reports of no sound on the dvd? I tried playing in my computer and there was no sound. I played other dvds with no problems. Any thoughts? I'm SOOO looking forward to it!!!

A!--Thanks for buying one of the first DVDs at our big Ninja DVD Launch party.
     Yes, unfortunatly, you are not the only one who is experiencing this problem.  I have recently learned that when you order a bulk under 500 DVD's from Amazon, they are un stamped (-R) version which does not play in a small percentage of old DVD players. According to Amazon... it is only 4% of the Players on the market.
     So, if your sound does not work, we suggest you try your computer, or another player in the house or maybe you can watch it with a friend's DVD player.
     I'm currently brainstorming with my production team on how we can order a small supply of Stamped (+R) DVD's so that I can offer an exchange, but until then, the only other suggestion I have is if you test your DVD within 2 weeks of purchase, I can offer an equal exchange for one of my books, or if you hand it back, I'll refund your money. Thanks for your understanding and patience.
xoxox
Kamala Devi
P.S.--The response I got:
No problem - it was my computer I tried it on but it is older. I'll see if I can get my newer dvd player connected. I'll still keep it, as I will get new computer one day! Or maybe I can find a friend to watch it with! I still need to get your autograph on it!