diff --git a/graphics/core.lua b/graphics/core.lua
index e993308..8f94b6f 100644
--- a/graphics/core.lua
+++ b/graphics/core.lua
@@ -7,7 +7,7 @@ local flasher = require("graphics.flasher")
 
 local core = {}
 
-core.version = "2.4.6"
+core.version = "2.4.7"
 
 core.flasher = flasher
 core.events = events
diff --git a/graphics/element.lua b/graphics/element.lua
index cde4fe7..665e29c 100644
--- a/graphics/element.lua
+++ b/graphics/element.lua
@@ -2,7 +2,6 @@
 -- Generic Graphics Element
 --
 
--- local log  = require("scada-common.log")
 local util = require("scada-common.util")
 
 local core = require("graphics.core")
@@ -476,10 +475,7 @@ function element.new(args, constraint, child_offset_x, child_offset_y)
 
         if args.parent ~= nil then
             -- remove self from parent
-            -- log.debug("removing " .. self.id .. " from parent")
             args.parent.__remove_child(self.id)
-        else
-            -- log.debug("no parent for " .. self.id .. " on delete attempt")
         end
     end
 
@@ -502,9 +498,12 @@ function element.new(args, constraint, child_offset_x, child_offset_y)
             self.next_id = self.next_id + 1
         end
 
-        table.insert(protected.children, child)
+        -- see #539 on GitHub
+        -- using #protected.children after inserting may give the wrong index, since if it inserts in a hole that completes the list then
+        -- the length will jump up to the full length of the list, possibly making two map entries point to the same child
+        protected.child_id_map[id] = #protected.children + 1
 
-        protected.child_id_map[id] = #protected.children
+        table.insert(protected.children, child)
 
         return id
     end
diff --git a/graphics/elements/ListBox.lua b/graphics/elements/ListBox.lua
index e1c8dec..470e723 100644
--- a/graphics/elements/ListBox.lua
+++ b/graphics/elements/ListBox.lua
@@ -1,6 +1,5 @@
 -- Scroll-able List Box Display Graphics Element
 
--- local log     = require("scada-common.log")
 local tcd     = require("scada-common.tcd")
 
 local core    = require("graphics.core")
@@ -153,7 +152,6 @@ return function (args)
             next_y = next_y + item.h + item_pad
             item.e.reposition(1, item.y)
             item.e.show()
-            -- log.debug("iterated " .. item.e.get_id())
         end
 
         content_height = next_y
@@ -212,7 +210,6 @@ return function (args)
     ---@param child graphics_element child element
     function e.on_added(id, child)
         table.insert(list, { id = id, e = child, y = 0, h = child.get_height() })
-        -- log.debug("added child " .. id .. " into slot " .. #list)
         update_positions()
     end
 
@@ -222,12 +219,10 @@ return function (args)
         for idx, elem in ipairs(list) do
             if elem.id == id then
                 table.remove(list, idx)
-                -- log.debug("removed child " .. id .. " from slot " .. idx)
                 update_positions()
                 return
             end
         end
-        -- log.debug("failed to remove child " .. id)
     end
 
     -- handle focus