diff --git a/basic_machines/chest.lua b/basic_machines/chest.lua
index 4230e89..d62849f 100644
--- a/basic_machines/chest.lua
+++ b/basic_machines/chest.lua
@@ -304,10 +304,10 @@ techage.register_node({"techage:chest_ta4"}, {
 		local meta = minetest.get_meta(pos)
 		local inv = meta:get_inventory()
 		local mem = techage.get_mem(pos)
-		if not mem.filter or not mem.filter["unconfigured"] then 
-			mem.filter = mConf.item_filter(pos, 50) 
-		end
-		mem.chest_configured = mem.chest_configured or #mem.filter["unconfigured"] < 50
+		
+		mem.filter = mem.filter or mConf.item_filter(pos, 50)
+		mem.chest_configured = mem.chest_configured or 
+				not mem.filter["unconfigured"] or #mem.filter["unconfigured"] < 50
 		
 		if inv:is_empty("main") then
 			return nil
@@ -337,10 +337,10 @@ techage.register_node({"techage:chest_ta4"}, {
 		local meta = minetest.get_meta(pos)
 		local inv = meta:get_inventory()
 		local mem = techage.get_mem(pos)
-		if not mem.filter or not mem.filter["unconfigured"] then 
-			mem.filter = mConf.item_filter(pos, 50) 
-		end
-		mem.chest_configured = mem.chest_configured or #mem.filter["unconfigured"] < 50
+		
+		mem.filter = mem.filter or mConf.item_filter(pos, 50)
+		mem.chest_configured = mem.chest_configured or 
+				not mem.filter["unconfigured"] or #mem.filter["unconfigured"] < 50
 		
 		if mem.chest_configured then
 			local name = item:get_name()
@@ -354,10 +354,10 @@ techage.register_node({"techage:chest_ta4"}, {
 		local meta = minetest.get_meta(pos)
 		local inv = meta:get_inventory()
 		local mem = techage.get_mem(pos)
-		if not mem.filter or not mem.filter["unconfigured"] then 
-			mem.filter = mConf.item_filter(pos, 50) 
-		end
-		mem.chest_configured = mem.chest_configured or #mem.filter["unconfigured"] < 50
+		
+		mem.filter = mem.filter or mConf.item_filter(pos, 50)
+		mem.chest_configured = mem.chest_configured or 
+				not mem.filter["unconfigured"] or #mem.filter["unconfigured"] < 50
 		
 		if mem.chest_configured then
 			local name = item:get_name()
diff --git a/basic_machines/distributor.lua b/basic_machines/distributor.lua
index ef06421..e4b2cee 100644
--- a/basic_machines/distributor.lua
+++ b/basic_machines/distributor.lua
@@ -219,7 +219,7 @@ local function push_item(pos, filter, itemstack, num_items, nvm)
 	local idx = 1
 	local num_pushed = 0
 	local num_ports = #filter
-	local randidx = permIdx[num_ports][math.random(1, #permIdx[num_ports])]
+	local randidx = permIdx[num_ports][math.random(1, #(permIdx[num_ports] or {0}))]
 	local amount = math.floor(math.max((num_items + 1) / num_ports, 1))
 	local num_of_trials = 0
 	while num_pushed < num_items and num_of_trials <= 8 do
diff --git a/basis/conf_inv.lua b/basis/conf_inv.lua
index 8b1badb..2963daf 100644
--- a/basis/conf_inv.lua
+++ b/basis/conf_inv.lua
@@ -25,7 +25,7 @@ function inv_lib.preassigned_stacks(pos, xsize, ysize)
 		local item_name = inv:get_stack("conf", idx):get_name()
 		if item_name ~= "" then
 			local x = (idx - 1) % xsize
-			local y = math.floor(idx / xsize)
+			local y = math.floor((idx - 1) / xsize)
 			tbl[#tbl+1] = "item_image["..x..","..y..";1,1;"..item_name.."]"
 		end
 	end
@@ -76,7 +76,7 @@ function inv_lib.allow_conf_inv_move(pos, from_list, from_index, to_list, to_ind
 end
 
 function inv_lib.put_items(pos, inv, listname, item, stacks, idx)
-	for _, i in ipairs(stacks) do
+	for _, i in ipairs(stacks or {}) do
 		if not idx or idx == i then
 			local stack = inv:get_stack(listname, i)
 			if stack:item_fits(item) then