It doesn't save the last couple seconds. If you place 3-4 blocks and leave the game and then come back they wont be there.
Confirmed in 1.7.1
Still have the same bug with 1.7 pre release
The game crash every time you put an item in the trade windows of the villager.
There is no crash report at all the game completely close by itself with snapshot 13w41a.
Still have the same bug on 14w07a