Bukkit

What steps will reproduce the problem?
1. When member go to creative world, then put items to backpack, then back to survival, these items still here.
2.
3.

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

What version of the product are you using?
We are using Spigot latest version. (1.8)

Do you have an error log of what happened?

Please provide any additional information below.

P/S: Sorry about my bad English.

Why not just dont give them permissions to use backpacks in the creative world? No need for backpacks in that mode anyway.