Turley,
I believe the Generic property listed in the tiledata tab should be renamed to Stackable. I have picked a few stackable and non-stackable items at random in the tiledata list and only the stackable ones have the Generic property check box enabled. Mind you I didn't look at all stackables and non-stackables. You have a look and see if you get similar results.
"Generic" property in the tiledata tab.
Moderator: POL Developer