I was getting a DNS error when connecting to update my gamertag in the Jan. 25 build of XBMC.

I altered the ip address in Q:\skin\MC360\extras\gamercardupdate.py on line 29 to reflect the working ip:

Maybe this can help someone else.

Nevermind, Kreten beat me to it:
http://forums.xbox-scene.com/index.php?showtopic=672727