Oops, my keyboard derped there. /give playerName atomicraft:compoundItem gives me the item but as soon as I even try to right click it, I get an itemstack out of bounds -1. Also, if I create a world, quit the game, relaunch mc and join that world, everything is still there meaning that the things only disappear when leaving and rejoining in the same game session. Ok heres my init code where the items are first referenced http://pastebin.com/hYRmwLfT and then my item init code http://pastebin.com/3dgyQ5bm