diff --git a/jme3-bullet-native/src/native/cpp/com_jme3_bullet_objects_PhysicsRigidBody.cpp b/jme3-bullet-native/src/native/cpp/com_jme3_bullet_objects_PhysicsRigidBody.cpp
index 2ea5557d0..e4d0c74bf 100644
--- a/jme3-bullet-native/src/native/cpp/com_jme3_bullet_objects_PhysicsRigidBody.cpp
+++ b/jme3-bullet-native/src/native/cpp/com_jme3_bullet_objects_PhysicsRigidBody.cpp
@@ -52,7 +52,9 @@ extern "C" {
         btMotionState* motionState = reinterpret_cast<btMotionState*>(motionstatId);
         btCollisionShape* shape = reinterpret_cast<btCollisionShape*>(shapeId);
         btVector3 localInertia = btVector3();
-        shape->calculateLocalInertia(mass, localInertia);
+	if(mass > 0){
+	        shape->calculateLocalInertia(mass, localInertia);
+	}
         btRigidBody* body = new btRigidBody(mass, motionState, shape, localInertia);
         body->setUserPointer(NULL);
         return reinterpret_cast<jlong>(body);
diff --git a/jme3-bullet/src/main/java/com/jme3/bullet/collision/shapes/CylinderCollisionShape.java b/jme3-bullet/src/main/java/com/jme3/bullet/collision/shapes/CylinderCollisionShape.java
index 35edb8449..4fe48f9b7 100644
--- a/jme3-bullet/src/main/java/com/jme3/bullet/collision/shapes/CylinderCollisionShape.java
+++ b/jme3-bullet/src/main/java/com/jme3/bullet/collision/shapes/CylinderCollisionShape.java
@@ -86,7 +86,9 @@ public class CylinderCollisionShape extends CollisionShape {
      */
     @Override
     public void setScale(Vector3f scale) {
-        Logger.getLogger(this.getClass().getName()).log(Level.WARNING, "CylinderCollisionShape cannot be scaled");
+    	 if (!scale.equals(Vector3f.UNIT_XYZ)) {
+    		 Logger.getLogger(this.getClass().getName()).log(Level.WARNING, "CylinderCollisionShape cannot be scaled");
+    	 }
     }
 
     public void write(JmeExporter ex) throws IOException {
diff --git a/jme3-core/src/main/java/com/jme3/material/Material.java b/jme3-core/src/main/java/com/jme3/material/Material.java
index 74748f578..b8d002932 100644
--- a/jme3-core/src/main/java/com/jme3/material/Material.java
+++ b/jme3-core/src/main/java/com/jme3/material/Material.java
@@ -35,7 +35,7 @@ import com.jme3.asset.AssetKey;
 import com.jme3.asset.AssetManager;
 import com.jme3.asset.CloneableSmartAsset;
 import com.jme3.export.*;
-import com.jme3.light.*;
+import com.jme3.light.LightList;
 import com.jme3.material.RenderState.BlendMode;
 import com.jme3.material.RenderState.FaceCullMode;
 import com.jme3.material.TechniqueDef.LightMode;
@@ -54,6 +54,8 @@ import com.jme3.texture.Image;
 import com.jme3.texture.Texture;
 import com.jme3.texture.image.ColorSpace;
 import com.jme3.util.ListMap;
+import com.jme3.util.SafeArrayList;
+
 import java.io.IOException;
 import java.util.*;
 import java.util.logging.Level;
@@ -749,8 +751,8 @@ public class Material implements CloneableSmartAsset, Cloneable, Savable {
         sortingId = -1;
     }
 
-    private int applyOverrides(Renderer renderer, Shader shader, List<MatParamOverride> overrides, int unit) {
-        for (MatParamOverride override : overrides) {
+    private int applyOverrides(Renderer renderer, Shader shader, SafeArrayList<MatParamOverride> overrides, int unit) {
+        for (MatParamOverride override : overrides.getArray()) {
             VarType type = override.getVarType();
 
             MatParam paramDef = def.getMaterialParam(override.getName());
@@ -777,7 +779,7 @@ public class Material implements CloneableSmartAsset, Cloneable, Savable {
     }
 
     private void updateShaderMaterialParameters(Renderer renderer, Shader shader,
-            List<MatParamOverride> worldOverrides, List<MatParamOverride> forcedOverrides) {
+                 SafeArrayList<MatParamOverride> worldOverrides, SafeArrayList<MatParamOverride> forcedOverrides) {
 
         int unit = 0;
         if (worldOverrides != null) {
@@ -945,7 +947,7 @@ public class Material implements CloneableSmartAsset, Cloneable, Savable {
         updateRenderState(renderManager, renderer, techniqueDef);
 
         // Get world overrides
-        List<MatParamOverride> overrides = geometry.getWorldMatParamOverrides();
+        SafeArrayList<MatParamOverride> overrides = geometry.getWorldMatParamOverrides();
 
         // Select shader to use
         Shader shader = technique.makeCurrent(renderManager, overrides, renderManager.getForcedMatParams(), lights, rendererCaps);
diff --git a/jme3-core/src/main/java/com/jme3/material/Technique.java b/jme3-core/src/main/java/com/jme3/material/Technique.java
index 8ca95b178..7128747c9 100644
--- a/jme3-core/src/main/java/com/jme3/material/Technique.java
+++ b/jme3-core/src/main/java/com/jme3/material/Technique.java
@@ -31,10 +31,10 @@
  */
 package com.jme3.material;
 
-import com.jme3.material.logic.TechniqueDefLogic;
 import com.jme3.asset.AssetManager;
 import com.jme3.light.LightList;
 import com.jme3.material.TechniqueDef.LightMode;
+import com.jme3.material.logic.TechniqueDefLogic;
 import com.jme3.renderer.Caps;
 import com.jme3.renderer.RenderManager;
 import com.jme3.scene.Geometry;
@@ -42,9 +42,8 @@ import com.jme3.shader.DefineList;
 import com.jme3.shader.Shader;
 import com.jme3.shader.VarType;
 import com.jme3.util.ListMap;
-import java.util.ArrayList;
+import com.jme3.util.SafeArrayList;
 import java.util.EnumSet;
-import java.util.List;
 
 /**
  * Represents a technique instance.
@@ -110,8 +109,8 @@ public final class Technique {
         }
     }
 
-    private void applyOverrides(DefineList defineList, List<MatParamOverride> overrides) {
-        for (MatParamOverride override : overrides) {
+    private void applyOverrides(DefineList defineList, SafeArrayList<MatParamOverride> overrides) {
+        for (MatParamOverride override : overrides.getArray()) {
             if (!override.isEnabled()) {
                 continue;
             }
@@ -134,8 +133,8 @@ public final class Technique {
      * @param rendererCaps The renderer capabilities which the shader should support.
      * @return A compatible shader.
      */
-    Shader makeCurrent(RenderManager renderManager, List<MatParamOverride> worldOverrides,
-            List<MatParamOverride> forcedOverrides,
+    Shader makeCurrent(RenderManager renderManager, SafeArrayList<MatParamOverride> worldOverrides,
+            SafeArrayList<MatParamOverride> forcedOverrides,
             LightList lights, EnumSet<Caps> rendererCaps) {
         TechniqueDefLogic logic = def.getLogic();
         AssetManager assetManager = owner.getMaterialDef().getAssetManager();
diff --git a/jme3-core/src/main/java/com/jme3/renderer/RenderManager.java b/jme3-core/src/main/java/com/jme3/renderer/RenderManager.java
index 50cc207f7..b07b95092 100644
--- a/jme3-core/src/main/java/com/jme3/renderer/RenderManager.java
+++ b/jme3-core/src/main/java/com/jme3/renderer/RenderManager.java
@@ -83,7 +83,7 @@ public class RenderManager {
     private Material forcedMaterial = null;
     private String forcedTechnique = null;
     private RenderState forcedRenderState = null;
-    private final List<MatParamOverride> forcedOverrides = new ArrayList<>();
+    private final SafeArrayList<MatParamOverride> forcedOverrides = new SafeArrayList<>(MatParamOverride.class);
     private int viewX, viewY, viewWidth, viewHeight;
     private final Matrix4f orthoMatrix = new Matrix4f();
     private final LightList filteredLightList = new LightList(null);
@@ -462,7 +462,7 @@ public class RenderManager {
      *
      * @return The forced material parameters.
      */
-    public List<MatParamOverride> getForcedMatParams() {
+    public SafeArrayList<MatParamOverride> getForcedMatParams() {
         return forcedOverrides;
     }
 
diff --git a/jme3-core/src/main/java/com/jme3/scene/Spatial.java b/jme3-core/src/main/java/com/jme3/scene/Spatial.java
index d0369ca3c..bbb795fdf 100644
--- a/jme3-core/src/main/java/com/jme3/scene/Spatial.java
+++ b/jme3-core/src/main/java/com/jme3/scene/Spatial.java
@@ -138,8 +138,8 @@ public abstract class Spatial implements Savable, Cloneable, Collidable, Cloneab
     protected LightList localLights;
     protected transient LightList worldLights;
 
-    protected ArrayList<MatParamOverride> localOverrides;
-    protected ArrayList<MatParamOverride> worldOverrides;
+    protected SafeArrayList<MatParamOverride> localOverrides;
+    protected SafeArrayList<MatParamOverride> worldOverrides;
 
     /** 
      * This spatial's name.
@@ -207,8 +207,8 @@ public abstract class Spatial implements Savable, Cloneable, Collidable, Cloneab
         localLights = new LightList(this);
         worldLights = new LightList(this);
 
-        localOverrides = new ArrayList<>();
-        worldOverrides = new ArrayList<>();
+        localOverrides = new SafeArrayList<>(MatParamOverride.class);
+        worldOverrides = new SafeArrayList<>(MatParamOverride.class);
         refreshFlags |= RF_BOUND;
     }
 
@@ -432,7 +432,7 @@ public abstract class Spatial implements Savable, Cloneable, Collidable, Cloneab
      *
      * @return The list of local material parameter overrides.
      */
-    public List<MatParamOverride> getLocalMatParamOverrides() {
+    public SafeArrayList<MatParamOverride> getLocalMatParamOverrides() {
         return localOverrides;
     }
 
@@ -446,7 +446,7 @@ public abstract class Spatial implements Savable, Cloneable, Collidable, Cloneab
      *
      * @return The list of world material parameter overrides.
      */
-    public List<MatParamOverride> getWorldMatParamOverrides() {
+    public SafeArrayList<MatParamOverride> getWorldMatParamOverrides() {
         return worldOverrides;
     }
 
@@ -1384,8 +1384,8 @@ public abstract class Spatial implements Savable, Cloneable, Collidable, Cloneab
             clone.localLights.setOwner(clone);
             clone.worldLights.setOwner(clone);
 
-            clone.worldOverrides = new ArrayList<MatParamOverride>();
-            clone.localOverrides = new ArrayList<MatParamOverride>();
+            clone.worldOverrides = new SafeArrayList<>(MatParamOverride.class);
+            clone.localOverrides = new SafeArrayList<>(MatParamOverride.class);
 
             for (MatParamOverride override : localOverrides) {
                 clone.localOverrides.add((MatParamOverride) override.clone());
@@ -1524,16 +1524,22 @@ public abstract class Spatial implements Savable, Cloneable, Collidable, Cloneab
     }
 
     public void setUserData(String key, Object data) {
-        if (userData == null) {
-            userData = new HashMap<String, Savable>();
-        }
-
-        if(data == null){
-            userData.remove(key);
-        }else if (data instanceof Savable) {
-            userData.put(key, (Savable) data);
+        if (data == null) {
+            if (userData != null) {
+                userData.remove(key);
+                if(userData.isEmpty()) {
+                    userData = null;
+                }
+            }
         } else {
-            userData.put(key, new UserData(UserData.getObjectType(data), data));
+            if (userData == null) {
+                userData = new HashMap<String, Savable>();
+            }
+            if (data instanceof Savable) {
+                userData.put(key, (Savable) data);
+            } else {
+                userData.put(key, new UserData(UserData.getObjectType(data), data));
+            }
         }
     }
 
@@ -1598,7 +1604,7 @@ public abstract class Spatial implements Savable, Cloneable, Collidable, Cloneab
         capsule.write(shadowMode, "shadow_mode", ShadowMode.Inherit);
         capsule.write(localTransform, "transform", Transform.IDENTITY);
         capsule.write(localLights, "lights", null);
-        capsule.writeSavableArrayList(localOverrides, "overrides", null);
+        capsule.writeSavableArrayList(new ArrayList(localOverrides), "overrides", null);
 
         // Shallow clone the controls array to convert its type.
         capsule.writeSavableArrayList(new ArrayList(controls), "controlsList", null);
@@ -1622,11 +1628,13 @@ public abstract class Spatial implements Savable, Cloneable, Collidable, Cloneab
         localLights = (LightList) ic.readSavable("lights", null);
         localLights.setOwner(this);
 
-        localOverrides = ic.readSavableArrayList("overrides", null);
-        if (localOverrides == null) {
-            localOverrides = new ArrayList<>();
+        ArrayList<MatParamOverride> localOverridesList = ic.readSavableArrayList("overrides", null);
+        if (localOverridesList == null) {
+            localOverrides = new SafeArrayList<>(MatParamOverride.class);
+        } else {
+            localOverrides = new SafeArrayList(MatParamOverride.class, localOverridesList);
         }
-        worldOverrides = new ArrayList<>();
+        worldOverrides = new SafeArrayList<>(MatParamOverride.class);
 
         //changed for backward compatibility with j3o files generated before the AnimControl/SkeletonControl split
         //the AnimControl creates the SkeletonControl for old files and add it to the spatial.
diff --git a/jme3-core/src/main/java/com/jme3/util/SafeArrayList.java b/jme3-core/src/main/java/com/jme3/util/SafeArrayList.java
index a0657c753..30593cd4b 100644
--- a/jme3-core/src/main/java/com/jme3/util/SafeArrayList.java
+++ b/jme3-core/src/main/java/com/jme3/util/SafeArrayList.java
@@ -258,7 +258,7 @@ public class SafeArrayList<E> implements List<E>, Cloneable {
             if( o1 == null || !o1.equals(o2) )
                 return false;
         }
-        return !(i1.hasNext() || !i2.hasNext());
+        return !(i1.hasNext() || i2.hasNext());
     }
 
     public int hashCode() {
diff --git a/jme3-jbullet/src/main/java/com/jme3/bullet/collision/shapes/CylinderCollisionShape.java b/jme3-jbullet/src/main/java/com/jme3/bullet/collision/shapes/CylinderCollisionShape.java
index 1a33c97fe..a41974d00 100644
--- a/jme3-jbullet/src/main/java/com/jme3/bullet/collision/shapes/CylinderCollisionShape.java
+++ b/jme3-jbullet/src/main/java/com/jme3/bullet/collision/shapes/CylinderCollisionShape.java
@@ -90,7 +90,9 @@ public class CylinderCollisionShape extends CollisionShape {
      */
     @Override
     public void setScale(Vector3f scale) {
-        Logger.getLogger(this.getClass().getName()).log(Level.WARNING, "CylinderCollisionShape cannot be scaled");
+    	 if (!scale.equals(Vector3f.UNIT_XYZ)) {
+    		 Logger.getLogger(this.getClass().getName()).log(Level.WARNING, "CylinderCollisionShape cannot be scaled");
+    	 }
     }
 
     public void write(JmeExporter ex) throws IOException {