It is possible to stack some things that normally don't stack within a crafting kit. Furthermore, it is possible to add an artifact item to a kit stack at which point the artifact becomes normal (one item of the stack). As an aside (and further question/possible bug with stacking) - why don't things that can stack always stack? I've had oil of vitriol form stacks of one to three items. However, sometimes a particular item won't stack with any others.
I have found the stack bug sometimes occurs when you have a stack of items, save, reload, and then try to add an item.
Yeah, reloading a save will cause potions to stop stacking properly. I believe this is already fixed in the latest Dev version, so it should go away once 1.0.4 hits.
