The Lost Mistwhisper Treasure

Typically this quest will not work if you loot the object first and then kill the boss. Wowhead from 3.3.5 says to walk near the shrine to spawn the boss, kill him, then loot the object. Walking near the shrine does not spawn the boss I have found (on Icecrown). Hopefully this answer is found when searching the quest title.

Thought I would post a work-around I found to complete this quest today:
1. Right click the shrine but DO NOT LOOT THE OBJECT. Close the loot box pop-up
2. The boss will spawn on his proto drake. Target the boss ONLY and kill him FIRST (not the drake).
3. When completing the quest as a warlock I had my pet tank the drake. I then looted the object, turned and killed the drake, and then turned in the quest. It's possible that you can kill the drake and then loot the object but your results may vary.

Good luck :)

Update:
Tried today on a paladin. I followed the above instructions like before-- The attack time for the proto drake is slow enough that you can loot the orb between its attacks. I killed the boss (not the drake), looted the orb by timing the loot window, and then killed the drake.

Tyvm m8. Being trying for about 30min with no luck. This drill worked!