If I read your original post correctly, you had several problems happening at about the same time.
There was the alien abduction, which
can happen any time a villager is "deleted" from the game (by burial or decomposition). Leaving your corpses laying around is no guarantee that you won't see vanishing villagers. You were, indeed, healing a sick villager when that happened.
You also said:
Quote:
Regardless of whether I dragged the sick person to the healer or vise versa, they either ran away or embraced. I made several attempts to heal her, but they were more interested in makeing babies, despite the fact that she was sick.
That's why I offered an explanation of the difference between being sick and weakened. I've never seen any villagers try to embrace when the "target" actually shows a status of "sick."
As for the vanishing villager bug, only living villagers will vanish. And, by all reports, it's only when you're dragging them around during the time that burials are taking place, or shortly thereafter. We will all be happy campers when that bug is fixed. It's regrettable that it wasn't caught and fixed before release, but it's being corrected for the v1.1 update. The only thing we can do until then is to provide a workaround. That bug is pretty rare and most people never see the vanishing villagers - I've been playing/testing the game for 6 months and have never seen it in the many, many games that I've "played."