On the quest "The Family Crypt" in The Agamand Mills (Tirisfal Glades)
When attacking Captain Dargol, it doesn't matter if it's with a ranged or melee attack he starts floating up into the sky and you have to hunt him down before you can actually fight him.
He seems to appear somewhere to the right of the crypt.
now i thought, a dirty way was to root the npc so that it wont go beserk and float, maybe with sai, but that is not how it should be, it looks like a problem with the crypt, since there is in front another npc and when you aggro that from a different angel in the middle he is stuck in the middle. so it might be the crypt that is causing it.