Hey, I just lost one. Villager A died, the first one to die, and one of my other villagers (Villager B) was going to take him to the burial area. Villager C happened to get sick, and I dragged yet another villager (Villager D) on to the sick one. Villager D healed Villager C, then I was dragging her back down to harvest crops, and she disappeared when I dropped her. She no longer shows in the details screen, and my population is one shorter - as if she never existed. I have a Zire 71.