Here's a new one (for me): On Saturday the sound on my DINC stopped working completely. First, I could make calls but speakerphone would not click on; then I could make calls and could hear the person on the other end, but they couldn't hear me. Then, all sounds stopped working -- I couldn't hear them and they couldn't hear me, even though the call went through. At the same time, you could hear a high pitch whine. I rebooted a couple of times and nothing worked. Finally, I pulled the battery and put it back in and luckily it started working again. Anyone else have this problem, or know what causes it?