"Losing" sorted items

[isaacrules2010]

Expectation:
Chest has every item just sorted in order

Reality:
Items are Oredictionaried to be whatever appears first. (example: if i have 14 salmon and 10 cod, i will have 24 salmon or cod, whichever appears first in the arbitrary sort order) This happens with multiple items... different stone types, fish, leaves.

Also Breaks economyshopgui, though im not sure if that's an issue with this plugin or that one, given that it uses a chest as its gui.