Could you tell us exactly how you set it up (router settings, windows settings, router hardware, etc.), that might give us clues how to use it?
We haven't found any common settings between those who has the voice chat working. Today we found out that the in-game voice chat works for another player also, so total 3 players have got it working so far (and I'm one of them). For those who has it working, everything works, including the direct talk. I don't know which windows settings to look for, or router settings. For sound hardware I just have basic integrated Realtek AC97-compatible system, and one of the players who does not have in-game voice chat working has the same.
Many guys who used to have the voice chat working before 1.05 patch, doesn't hear anything anymore. I'll try to look if there is anything common in the hardware or settings for those who has it working.