uTorrent is a great graphical tool to activate Teredo IPv6 on Windows XP.However, uTorrent on Windows Vista is quite silly: with the IPv6-only tracker tracker.sixxs.net, uTorrent says “hostname not found”. Grrrr! And do remember: on Vista Teredo IPv6 is enabled by default, so IPv6 should work. Probably uTorrent is using Vista’s braindead name resolving, meaning: no AAAA lookups with Teredo IPv6.