Related: http://www.cardhunter.com/forum/threads/shop-bug.780/#post-18055 I am now able to successfully replicate (reproducible and consistent) multiple items without spending gold/pizza and abuse/exploit for gold and items. The primary culprit lies with dragging items outside of browser screen creating 'Error in ItemDisplay:nTransfer() - Either origin or destination is null or not ItemContainerDisplay' in log. The below creates multiple items in the chest shop and successfully claiming them into inventory. Note that my gold has not changed and I do not have extra copies of the items 'hidden' from screenshot. I have also tested against treasures (cf above url) and in loot found in adventures.
Hopefully that is the last item replication bug there is nothing ruins a economy like item replication <.<
