Seems like a few people who have tried out the threedegrees beta have been having some real problems with the IPv6 support.

John describes his experience: “I installed the threedegrees beta from Microsoft. Firstly just a laughable install for a consumer product — i had to download and install a separate system component, i had to reboot, i had to register AND i had to log in with my passport AND i had to provide the double secret beta key, and i had to use the miserable microsoft download manager. Then when i tried to use it, it gave me some error message about my IPv6 stack not being properly configured! an IPv6 stack that it had installed. Just hilarious — who would build a dependency on an IPv6 stack into a consumer product?“