I started playing Minecraft again on a new seed. And I found 2 villages. Both in a snowy area. Both with messed up farms because of the snow cover. I threw up a glass ceiling, plowed and planted, things are ripe, but the villagers wont work the fields, at all. They pick up food I throw at them so I think they are hungry but they do nothing to feed themselves like they used to a year ago, or whatever.
Am I missing something? Note that I am not trying to build an automated farm or anything. It's even regular village spawned fields. Just with a glass roof (and a few torches) I put up so it wouldn't get snowed over.