I hate to be a bastard about this, but I've been in a group the last two days and both days it dropped. Tuesday and Wednesday of this week. First time we handed it to our dirge and the jewelry box autopicked the Cartilage Earstud for him, he was able to get a GM to fix it and he got the drum. The next day it dropped and we offered it to our MT dirge (who always whines about the drum never dropping), and instead of waiting for the group invite to stick he zoned into a fresh zone and got a lock out timer!
The original loot timer expired, the exquisite chest disappeared and nobody got the jewelry box! Fun times, now we have to listen to our MT dirge complain for the next 100 years!

We petitioned it so hopefully somebody from the group will get the jewelry box.
Both groups had first timers in the zone, but I doubt that had anything to do with it. Good luck and phat lewtz!
Peace