I had this problem a long time ago, truthfully it varies from server to server and the set configuration on how they deal with looting. Say there was an effect that came on when looting, or the monsters looted some sort of quest item, or even that the items.obt is different from the official one. Elfbot is meant to work for Tibia, not necessarily OTs, sorry to burst your bubble, it just doesn't work that way sometimes.