My dwarves began starving to death soon after I introduced a special pile for seeds near my farm, along with a pair of auxiliary food stores away from the main supply dump. Every food stockpile in the joint is stacked to the rafters with prepared food, yet everyone is begging off work to go hunt for vermin shortly before starving to death. Not sure if it was the seed pile or the new prepared food/drink piles that caused it. I reverted to an old save and was able to reproduce it quite easily, then I created some new saves in the middle of the trouble.
Check out http://rharvey.home.die.net/dwarf for the saves.
save_starving_setup.zip illustrates the setup that leads me down the road to starvation. Notice that near my main gate I have 4 food stockpiles. These have all just recently been set to refuse plantable seeds. If you scroll just east of the river, you'll see some farms, and just to the right of them a room has been dug with a few newly added food stockpiles. One is set to accept only plantable seeds. One is set to accept prepared food and drink, with an order to pull from a main stockpile. The final one is set to accept only drinks, and likewise pulls from a main stockpile. If this runs for awhile we get to the next save...
save_starving_beginning.zip is a snapshot of the first time a peasant drops what he's doing to hunt for vermin. Every food pile in my fortress has plenty of prepared food in it (with the exception of the two that are set to refuse it).
save_starving_fullswing.zip is several minutes later, when the starving really gets going. Again, all the food piles have prepared food. What gives?
As a final test, I went back to the save_starving_setup snapshot, and immediately removed all of the new stockpiles, and reset all of my main stockpiles back to "Accept All." In other words, I reset the fort back to the state in which it had been thriving for years. And 10 minutes later my peeps started hunting vermin again. This is no good. Who will be left to man the doomsday devices when the sieges begin anew?