I would suggest you make lock boxes pick-able from the "will not be traded slot"
The way that it works now is currently broken and the only way to make sure that you get 100% of your items is to level a rogue to 45 and pick all lock boxes yourself...which is silly.
Right now rogues can open your lock box and if it drops more than 1 item they can loot just 1 item and leave one in the box to keep for themselves. There is no way to know if the rogue has looted all the items.