That key might still have been blacklisted. I know that every Beta Tester was issued new keys for Build 5231 as the other keys were blacklisted for 5112 and 5219 since it was leaked. So i am willing to guess that they deactivated everybody with that key now. I would ask your buddy if the key was blacklisted or not. I am willing to bet that it was. It probably eiterh began with GKFV7 or maybe Q8WDJ. If so both of those were blacklisted and are not able to be used anymore. Need to find a different key in order to use Vista now. Even 5112 and 5219.