diff --git a/GUI/PropertyWindow/PropertyWindow.Blocks.cs b/GUI/PropertyWindow/PropertyWindow.Blocks.cs
index 463c33896..5059f2fd2 100644
--- a/GUI/PropertyWindow/PropertyWindow.Blocks.cs
+++ b/GUI/PropertyWindow/PropertyWindow.Blocks.cs
@@ -63,7 +63,7 @@ namespace MCGalaxy.Gui {
                 }
             }
             
-            BlockProps.Save("core", Block.Props, true);
+            BlockProps.Save("core", Block.Props, i => true);
             BlockPerms.Save();
             Block.SetBlocks();
             LoadBlocks();
diff --git a/MCGalaxy/Blocks/BlockProperties.cs b/MCGalaxy/Blocks/BlockProperties.cs
index e072f2d00..cb2f7f683 100644
--- a/MCGalaxy/Blocks/BlockProperties.cs
+++ b/MCGalaxy/Blocks/BlockProperties.cs
@@ -77,7 +77,7 @@ namespace MCGalaxy.Blocks {
         }
         
         
-        public static void Save(string group, BlockProps[] scope, bool custom) {
+        public static void Save(string group, BlockProps[] scope, Predicate<int> selector) {
             if (!Directory.Exists("blockprops"))
                 Directory.CreateDirectory("blockprops");
             
@@ -86,11 +86,8 @@ namespace MCGalaxy.Blocks {
                 w.WriteLine("# id : Is rails : Is tdoor : Is door : Is message block : Is portal : " +
                             "Killed by water : Killed by lava : Kills players : death message : Animal AI type");
                 for (int i = 0; i < scope.Length; i++) {
-                    if (!scope[i].Changed) continue;
+                    if (!scope[i].Changed || !selector(i)) continue;
                     BlockProps props = scope[i];
-                    
-                    // Don't save physics blocks
-                    if (custom && (i > Block.CpeCount && i < Block.Count)) continue;
                     // Convert ext to raw ids
                     int id = i >= Block.Count ? (i - Block.Count) : i;
                     
@@ -121,7 +118,7 @@ namespace MCGalaxy.Blocks {
                 byte raw;
                 if (!Byte.TryParse(parts[0], out raw)) {
                     Server.s.Log("Invalid line \"" + line + "\" in " + group + " block properties");
-                    continue;                   
+                    continue;
                 }
                 int idx = raw;
                 if (custom && raw >= Block.CpeCount) idx += Block.Count;
diff --git a/MCGalaxy/Blocks/ExtBlock.cs b/MCGalaxy/Blocks/ExtBlock.cs
index 3a6fe6861..7031fc106 100644
--- a/MCGalaxy/Blocks/ExtBlock.cs
+++ b/MCGalaxy/Blocks/ExtBlock.cs
@@ -66,6 +66,12 @@ namespace MCGalaxy {
             return new ExtBlock(Block.custom_block, raw);
         }
         
+        public static ExtBlock FromIndex(int index) {
+            if (index < Block.Count)
+                return new ExtBlock((byte)index, 0);
+            return new ExtBlock(Block.custom_block, (byte)(index - Block.Count));
+        }
+        
         /// <summary> Constructs an extended block. </summary>
         public static explicit operator ExtBlock(byte block) { return new ExtBlock(block, 0); }
         
diff --git a/MCGalaxy/Commands/World/CmdBlockProperties.cs b/MCGalaxy/Commands/World/CmdBlockProperties.cs
index c4d5749e6..72febb4e1 100644
--- a/MCGalaxy/Commands/World/CmdBlockProperties.cs
+++ b/MCGalaxy/Commands/World/CmdBlockProperties.cs
@@ -176,7 +176,7 @@ namespace MCGalaxy.Commands.World {
             scope[block.Index].Changed = true;
             
             if (scope == Block.Props) {
-                BlockProps.Save("core", scope, true);
+                BlockProps.Save("core", scope, i=> true);
                 Level[] loaded = LevelInfo.Loaded.Items;
                 
                 foreach (Level lvl in loaded) {
@@ -185,7 +185,7 @@ namespace MCGalaxy.Commands.World {
                 }
             } else if (scope == BlockDefinition.GlobalProps) {
                 Level[] loaded = LevelInfo.Loaded.Items;
-                BlockProps.Save("global", scope, false);
+                BlockProps.Save("global", scope, SelectGlobal);
                 
                 byte raw = block.RawID;
                 foreach (Level lvl in loaded) {
@@ -194,11 +194,22 @@ namespace MCGalaxy.Commands.World {
                     lvl.SetBlockHandler(block);
                 }                
             } else {
-                BlockProps.Save("lvl_" + level.name, scope, false);
+                BlockProps.Save("lvl_" + level.name, scope, i => SelectLevel(level, i));
                 level.SetBlockHandler(block);
             }
         }
         
+        static bool SelectGlobal(int i) {
+            ExtBlock block = ExtBlock.FromIndex(i);
+            return !block.IsPhysicsType && BlockDefinition.GlobalDefs[block.RawID] != null;
+        }
+        
+        static bool SelectLevel(Level lvl, int i) {
+            ExtBlock block = ExtBlock.FromIndex(i);
+            return !block.IsPhysicsType && 
+                lvl.CustomBlockDefs[block.RawID] != BlockDefinition.GlobalDefs[block.RawID];
+        }
+        
         static string BlockName(BlockProps[] scope, Level lvl, ExtBlock block) {
             if (scope == Block.Props) return Block.Name(block.RawID);
             BlockDefinition def = null;
diff --git a/MCGalaxy/Commands/building/CmdMessageBlock.cs b/MCGalaxy/Commands/building/CmdMessageBlock.cs
index 7f89b337b..bbf033579 100644
--- a/MCGalaxy/Commands/building/CmdMessageBlock.cs
+++ b/MCGalaxy/Commands/building/CmdMessageBlock.cs
@@ -205,7 +205,7 @@ namespace MCGalaxy.Commands.Building {
         static void GetCoreNames(List<string> names, Level lvl) {
             BlockProps[] props = lvl == null ? lvl.BlockProps : Block.Props;
             for (int i = Block.air; i < Block.Count; i++) {
-                ExtBlock block = new ExtBlock((byte)i, 0);
+                ExtBlock block = ExtBlock.FromIndex(i);
                 if (block.BlockID == Block.custom_block) continue;
                 
                 string name = Format(block, lvl, props);
diff --git a/MCGalaxy/Commands/building/CmdPortal.cs b/MCGalaxy/Commands/building/CmdPortal.cs
index 362ffec49..f62abc795 100644
--- a/MCGalaxy/Commands/building/CmdPortal.cs
+++ b/MCGalaxy/Commands/building/CmdPortal.cs
@@ -207,7 +207,7 @@ namespace MCGalaxy.Commands.Building {
         static void GetCoreNames(List<string> names, Level lvl) {
             BlockProps[] props = lvl == null ? lvl.BlockProps : Block.Props;
             for (int i = Block.air; i < Block.Count; i++) {
-                ExtBlock block = new ExtBlock((byte)i, 0);
+                ExtBlock block = ExtBlock.FromIndex(i);
                 if (block.BlockID == Block.custom_block) continue;
                 
                 string name = Format(block, lvl, props);
diff --git a/MCGalaxy/Levels/Level.cs b/MCGalaxy/Levels/Level.cs
index 79beca082..cc8929612 100644
--- a/MCGalaxy/Levels/Level.cs
+++ b/MCGalaxy/Levels/Level.cs
@@ -504,9 +504,8 @@ namespace MCGalaxy {
         }
         
         public void SetBlockHandlers() {            
-            for (int i = 0; i < Block.Count; i++) {
-                SetBlockHandler(new ExtBlock((byte)i, 0));
-                SetBlockHandler(new ExtBlock(Block.custom_block, (byte)i));
+            for (int i = 0; i < BlockProps.Length; i++) {
+                SetBlockHandler(ExtBlock.FromIndex(i));
             }
         }
         
@@ -515,7 +514,7 @@ namespace MCGalaxy {
             if (GetBlockDef(block) == null) {
                 nonSolid = Block.Walkthrough(Block.Convert(block.BlockID));
             } else {
-                nonSolid = CustomBlockDefs[block.BlockID].CollideType != CollideType.Solid;
+                nonSolid = CustomBlockDefs[block.RawID].CollideType != CollideType.Solid;
             }
             
             int i = block.Index;