Confirmed in 1.4.6pre
With the save file provided they can easily reproduce, debug and fix that.
@Kumasasa : Why did you update fix version to "Minecraft 1.4.5" ? Has this been fixed ?
A bug report should contain only 1 bug report, see : http://help.mojang.com/customer/portal/articles/801354-writing-helpful-bug-reports-for-minecraft
Voted, I also realized that I can kill chicken that appear to be outside the fence when they are actually inside. The drop appears at the correct location (inside). I also find eggs outside of the fence.
Tested in 1.4.5, I can open chests holding a boat.
The stair will change or not according to your orientation when you place it. This is why it looks random, but when you understand how it works you can have precise control on the stair shape.
There is probably really another cave or small hole near, try using a transparent texture pack to find it.
Then it was coming from a mod.
17th duplicate
It is shift + left-click
To be honest this is far from game-breaking, I'm sure we can live with it until 1.5
Are you using PC, Mac or Linux ?
This is the first time I see part of houses erased by chunks, I believe this is a bug. I also never saw any other structures cut by chunks. Definitely not something "normal"
Maybe I'm wrong, but there is no /warp or /w command in vanilla Minecraft. The command is /tp. I believe you are playing on a Bukkit server with plugins or modded Minecraft.
I believe this is fixed => MC-10778