If you have a dimond as a hat you can't sell dimonds in /shop

[MasterScare]

What is the bug: If you buy a hat from the server forms and but a diamond as your hat and then try to sell diamonds in the shop it doesn't work

http://imgur.com/a/l7CEU

Where is this bug located: All shops

How can we recreate it: Buy a hat, choose a diamond as your hat and then sell diamonds

Not really a game breaking glitch just something that annoys me and could be fixed