I can confirm this. To be precise, if at one point the villager inventory get filled, he will not harvest anymore. You can force him to empty his inventory by harvesting the crop yourself, he will replant. But it's a tidous process (8 stacks _). In addition, the farmer should still be able to toss the food to another villager, but he also stop doing that when he's full.
No news at all ?
I had the same conclusion has Fienjox. My hut generated in 14w08 (-5483930890225577113, -1904 -1312) spawn witches in every floors except for the one below the roof. This layer of the hut spawn regular mobs like every block in the swamp. If i revert to 1.7.4, this layer spawn only witches again. 14w10 didn't fix it.
I've done some test in the Snapshot 14w11b and using NBT Explorer to check the results :
Farmer stop harvesting as soon they hit 60 items in their inventory, it does not matter if the items are split into multiple slots.
If by any means (toss at another villager, plant on new crop, etc.) the items count in their inventory drop below 60 they start harvesting again.
It affect carrots, potatoes, wheat, seeds, bread.