Got the key from the first room, entered the 2nd, box didn't spawn.
(https://dl.dropboxusercontent.com/u/26012607/Shot00060.jpg)
unlucky
My cp did it more then 10x, never bugged. Unlucky i guess.
Went in again 1h later. Went into the 2nd room, box spawned, killed mobs, didn't get the key, suddenly all mobs disappeared and nothing is respawning.
(https://dl.dropboxusercontent.com/u/26012607/Shot00061.jpg)
just tested right now, it did not happen to me, all fine o.O
i know it's not a permanent thing cuz i went in again and it was fine. It had to do with all these NPC resets that have been going on (involving Tezza and respawning it).