Plots are crushing when unclaimed!

What steps will reproduce the problem?

As I see, not all servers are suffering this problem, however,
1. Create a town
2. Unclaim a plot(or delete town)
3. The land(unclaimed plots) seems to recover, but creates a huge canyon(?) in 
the world.

What is the expected output? What do you see instead?

It just have to stay as it was, but huge canyons.
I saw some similar issues, but this seems to be much bigger.

What is your towny build?

0.80.0.16

What is your bukkit build?

1.2.5-R1.0 #2149

What operating system?

Windows Server 2008

* Installed Plugins

AuthMe
AutoMessage
BKCommonLib
BorderGuard
ChatManager
ChestShop
iConomy
IPCompare
Lift
ModifyWorld
NoLagg[Examine/ItemBuffer/ItemStacker/Lighting/Monitor/TNT]
Orebfuscator
PermissionsEx
Questioner
Register
Towny, TownyChat
Vault

- This server is managed by 3 managers(including myself), so I don't know why 
some plugins are there.

Original issue reported on code.google.com by williamb...@gmail.com on 1 May 2012 at 3:50

Merged into: #878

Attachments:

MrNaikito / towny

Plots are crushing when unclaimed! #989