Index: /trunk/autoquest-ui-swt/src/main/java/de/ugoe/cs/autoquest/ui/swt/VisualizationUtils.java
===================================================================
--- /trunk/autoquest-ui-swt/src/main/java/de/ugoe/cs/autoquest/ui/swt/VisualizationUtils.java	(revision 1920)
+++ /trunk/autoquest-ui-swt/src/main/java/de/ugoe/cs/autoquest/ui/swt/VisualizationUtils.java	(revision 1921)
@@ -119,5 +119,5 @@
             
             if (parent.getData() instanceof ITask) {
-                contextValue = taskInfo.getMeasureValue(metrics[i], (ITask) parent.getData());
+                contextValue = taskInfo.getMeasureValue(metrics[i]);
             }
             
@@ -197,15 +197,24 @@
                                            final SelectionAdapter menuItemSelectionAdapter)
     {
-        final Menu menu = new Menu(tree);
-        tree.setMenu(menu);
+        Menu menu = tree.getMenu();
+        
+        if (menu == null) {
+            menu = new Menu(tree);
+            tree.setMenu(menu);
+        }
+        
+        final Menu finalMenu = menu;
+        
         menu.addMenuListener(new MenuAdapter() {
             public void menuShown(MenuEvent e) {
-                MenuItem[] items = menu.getItems();
+                MenuItem[] items = finalMenu.getItems();
                 for (int i = 0; i < items.length; i++) {
-                    items[i].dispose();
+                    if (menuItemText.equals(items[i].getText())) {
+                        items[i].dispose();
+                    }
                 }
                 
                 if (selectedItemDataType.isInstance(tree.getSelection()[0].getData())) {
-                    MenuItem newItem = new MenuItem(menu, SWT.NONE);
+                    MenuItem newItem = new MenuItem(finalMenu, SWT.NONE);
                     newItem.setText(menuItemText);
                     newItem.addSelectionListener(menuItemSelectionAdapter);