Sean Peacock

I have a similar problem with zombies attacking villagers behind doors.
Version 1.8

To recreate: build a small house, and place a villager or two in it next to the door. spawn some zombies outside and watch.

I think a simple solution would be to make the villager AI stay as far from the zombie as possible even if the door is closed.

It sounds like the tamed / sitting code was changed between the versions that you switched between. I label each of my save games with the version number that I created it in just to avoid similar problems.

I have this problem in 1.8. The tamed wolves stop following me when they lose sight of me. they rarely teleport to me, and when they do they tend to teleport into a cactus. Occasionally a lost wolf will find me when I am exploring however they tend to get lost again quickly.

I noticed that the villagers have spread out as well in 14w06b, but in 14w07a they seem to hang out at one end of town again although in different houses. I will hang around to see if the door locator was just reset and they need to find the doors again.
I might create another village elsewhere to test this where closer to my current build site.
The new trade options seem to show up after making a trade with the old villagers. I am going to make some more homes to see what happens when they breed.

Now if you are talking about the multiple branch trees I had to grow this one in 1.7.4

Here are two screenshots from the latest snapshot and two different seeds. Complete with large oak trees, cords, and seed.

I built a rail loop around my village to get villagers to the other side of the village, but they keep going back to the same building regardless of where I release them from the minecart. I even cured a zombie in one of the unused houses, and after he was cured he went to the other side to socialize with the rest. Interestingly they congregate in a house that I built, as opposed to the ones generated by the game. ver 1.7.4

Unless the zombie changed into a villager it will despawn when the difficulty is changed to peaceful. This is because until the change is complete it is still a hostile zombie. That is also why it will burn in the sun and attach other villagers.

fixed in 1.7.4 - I created a new world in creative mode and found an appropriate forest.
seed: -766357888
x:-556
z:980