Bukkit

What steps will reproduce the problem?
1.Get a two high plant.
2.Change upper and lower part to different metadatas.
3.Change the upper part rapidly.

What is the expected output? What do you see instead?
Minecraft crashes and the server outputs an extremly long error.

What version of the product are you using?
V1.1 for minecraft 1.6.4 on a 1.7.2 server.

Do you have an error log of what happened?
Yes for the server and the client but it's extremly long and from what I've read it has to do with the rendering of the plant.

Please provide any additional information below.
As a temporary quick fix I would suggest to disallow changing the 2 high plants.

I had the same issue. I actually had to go in and delete the chunk in MCEdit. Any chance of getting a fix on this?