Hello, I have a new Twinhead Durabook D15TS running Windows XP Pro, with a Realtek audio device. When I insert the headphone plug into the jack, my speakers continue to play. This defeats the purpose of headphones. I called Twinhead (now Gamma Tech). The tech tested his headphones on a laptop identical to mine and it worked properly. This was no help. I've tried 4 different sets of headphones, all do not mute the speakers. I've searched the web, and I can see this isn't a random problem, it happens quite frequently, and no one's been able to fix it. I'm curious as to what the genius' here think. Thanks for your time.