I've noticed it now and again. My villagers seem to disappear over night. They aren't dying because usually it happens if I leave the village for a long period of time and come back, certain villagers don't come back. Recently I returned to find four of my guards were missing as well as one of my villagers had managed to clone herself... it was very strange because she was married and under both of Whitney the Farmer I had it said (married to) and the husband had nothing but he is still there. I don't know if it is possible that I have too many villagers for the village because I have removed and replaced doors so I don't know if I have enough doors to support the villagers or if that even matters in this MOD, I have only been using it for several weeks. I do have the most recent 4.0.3 for 1.7.2 and also runs several other mods (The Dalek Mod, MrCrayfish Furniture Mod, SDXC recipier and of course the most recent RadixCore as well.)

I can't seem to reproduce any issues with villagers disappearing - I would assume they are dying or simply wandering off. The clone is worrying, though. These may just be simple client-server sync issues. I'll be looking at those for MCA 4.1.0.