Torchlight II

Torchlight II

SynergiesMOD (v.1375)
Transmuter bug
I started a new game and have been trying to fill out my transmuting recipes. I know you can put four unique items in, to get a random item. I shift-clicked on the items but the would only go to the bottom two spaces. If I manually put an item in either of the top two spaces, the item will disappear.
What are my options?