[BUG]Quest: The Sum is Greater Than the Parts

Just tried to do the quest "The Sum is Greater Than the Parts" in Icecrown, and it is currently un-doable.
The first time I tried it, the third wave spawned and then despawned. After that, Dr. Terrible and his puppies spawned, ran to Nergeld, and then despawned.
The second time I tried it, everything worked fine until Dr. Terrible and his puppies spawned. Again, they ran to Nergeld and then despawned.
The third time, the second wave spawned and then despawned, followed by the third wave and Dr. Terrible doing the same thing.

Edit: It appears that the quest is a requirement in order to access all the later Jotunheim quests, so that chain is currently un-doable as well.