diff --git a/org.eclipse.scout.rt.client.test/src/test/java/org/eclipse/scout/rt/client/ui/basic/tree/AbstractTreeTest.java b/org.eclipse.scout.rt.client.test/src/test/java/org/eclipse/scout/rt/client/ui/basic/tree/AbstractTreeTest.java
index a2f6074bb48..ca7e0c03401 100644
--- a/org.eclipse.scout.rt.client.test/src/test/java/org/eclipse/scout/rt/client/ui/basic/tree/AbstractTreeTest.java
+++ b/org.eclipse.scout.rt.client.test/src/test/java/org/eclipse/scout/rt/client/ui/basic/tree/AbstractTreeTest.java
@@ -20,7 +20,6 @@
 import org.eclipse.scout.rt.platform.util.CollectionUtility;
 import org.eclipse.scout.rt.shared.data.basic.FontSpec;
 import org.eclipse.scout.rt.testing.platform.runner.PlatformTestRunner;
-import org.junit.After;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
@@ -43,7 +42,6 @@ public class AbstractTreeTest {
 
   @Before
   public void setup() {
-    //BEANS.get(IExtensionRegistry.class).register(TreeNodeExtension.class);
     m_tree = new P_Tree();
     m_node1 = new P_TreeNode("node1");
     m_node2 = new P_TreeNode("node2");
@@ -60,11 +58,6 @@ public void setup() {
     m_tree.addTreeListener(m_treeListener);
   }
 
-  @After
-  public void tearDown() {
-    //BEANS.get(IExtensionRegistry.class).deregister(TreeNodeExtension.class);
-  }
-
   @Test
   public void testNodeChangedSingleEvents() {
 
@@ -253,7 +246,7 @@ protected boolean containsEvent(List<TreeEvent> events, int eventType, ITreeNode
 
   private static void assertDisposed(ITestDisposable... disposables) {
     for (ITestDisposable disposable : disposables) {
-      assertTrue("should be desposed, but is not: " + disposable.getName(), disposable.isDisposed());
+      assertTrue("should be disposed, but is not: " + disposable.getName(), disposable.isDisposed());
     }
   }
 
@@ -522,13 +515,11 @@ private interface ITestDisposable {
     boolean isDisposed();
 
     String getName();
-
   }
 
   public static class P_TreeNode extends AbstractTreeNode implements ITestDisposable {
     boolean m_disposeInternalCalled = false;
     boolean m_execDisposeCalled = false;
-    boolean m_additionalDisposeCalled = false;
 
     private String m_name;
 
@@ -543,7 +534,7 @@ public String getName() {
 
     @Override
     public boolean isDisposed() {
-      return m_disposeInternalCalled && m_execDisposeCalled && m_additionalDisposeCalled;
+      return m_disposeInternalCalled && m_execDisposeCalled;
     }
 
     @Override
@@ -556,10 +547,6 @@ public void disposeInternal() {
       super.disposeInternal();
       m_disposeInternalCalled = true;
     }
-
-    public void additionalDispose() {
-      m_additionalDisposeCalled = true;
-    }
   }
 
   public static class P_TestMenu extends AbstractMenu implements ITestDisposable {
@@ -586,5 +573,4 @@ public void disposeActionInternal() {
       m_disposed = true;
     }
   }
-
 }
diff --git a/org.eclipse.scout.rt.client/src/main/java/org/eclipse/scout/rt/client/ui/basic/tree/AbstractTreeNode.java b/org.eclipse.scout.rt.client/src/main/java/org/eclipse/scout/rt/client/ui/basic/tree/AbstractTreeNode.java
index 1d2c47f2936..29c9cc664a7 100644
--- a/org.eclipse.scout.rt.client/src/main/java/org/eclipse/scout/rt/client/ui/basic/tree/AbstractTreeNode.java
+++ b/org.eclipse.scout.rt.client/src/main/java/org/eclipse/scout/rt/client/ui/basic/tree/AbstractTreeNode.java
@@ -315,9 +315,7 @@ public void setFilterAccepted(boolean b) {
 
   @Override
   public void resetFilterCache() {
-    synchronized (this) {
-      m_filteredChildNodes = null;
-    }
+    m_filteredChildNodes = null;
   }
 
   @Override
@@ -1015,6 +1013,12 @@ public final void dispose() {
     catch (RuntimeException e) {
       LOG.warn("Exception while disposing node.", e);
     }
+    try {
+      execDispose();
+    }
+    catch (RuntimeException e) {
+      LOG.warn("Exception while disposing node.", e);
+    }
     finally {
       setDisposing(false);
     }