When using the main inventory, I click on the crafting guide button to find that it gives me the option to craft a stone stairs, slabs and walls of all sorts (andesite, granite, stone, etc.) When clicking on the recipe it places 1 of those specific blocks used for making the item into the 4x4 crafting square. I can only presume that, that isn't supposed to happen. I apologise if someone has made a post about this already but hope to see this fixed in next snapshot.