Bukkit

What steps will reproduce the problem?
1.Create Shop
2. unload chunk for couple of min
3. and return back to allow pickup of item on top of chest.

What is the expected output? What do you see instead?
Items on to of shops should not be able to pickup

What version of the product are you using?
Shop - a simple, intuitive shop plugin 1.5.2.1

Do you have an error log of what happened?
no error in console

Please provide any additional information below.
Items on top of chest are able to be pick op by players when unloading chunk
allow players to create shops with diamond with a hope under chest and unload chunk and return allow player to brake signing and doop the item.