I have looked around and not seen this problem yet. I am on Windows 7 (64-bit) and when I talk on TeamSpeak3, if others are talking at the same time it will lower their volume in my headset. Basically while I am talking, I can no longer hear others until I stop, then they go back to normal volume.
Is this a known issue, and/or has it been solved? Would really like to fix this because it's really annoying.