Bukkit

What steps will reproduce the problem?
1. For the display items duplicating - Server reloading or restarting
2. For disappearing display items (this breaks the shops, but only happens to some) - No idea, just happened today.
3.

What is the expected output? What do you see instead?
For items not to duplicate all named "DisplayItem23G@" or whatever; and
for shops not to be wiped.
What version of the product are you using?
The latest one, for 1.7.2

Do you have an error log of what happened?
No

Please provide any additional information below.

Can confirm bug. - can reproduce with:

1. place shop
2. tp some number of chunks away
3. tp back
4. disable plugin (via plugman http://dev.bukkit.org/bukkit-plugins/plugman/)