tree node problem zk 5.0.7

...
        private void createMenu(ApplicationMenu appMenu){
		final List<MenuItem> menuList = appMenu == null ? null : appMenu.getMenuList();
		if(menuList != null && !menuList.isEmpty()){
			
			List <DefaultTreeNode> children = createMenu(menuList);
			DefaultTreeNode root = new DefaultTreeNode("ROOT", children);
			
			DefaultTreeModel treeModel = new DefaultTreeModel(root);
			menuTree.setModel(treeModel);
		}
		
	}

	private List<DefaultTreeNode> createMenu(List<MenuItem> children){
		List<DefaultTreeNode> childrenList = new ArrayList<DefaultTreeNode>();
		if(children != null && !children.isEmpty()){
			for(MenuItem menuItem : children){
				DefaultTreeNode node = new DefaultTreeNode(menuItem, createMenu(menuItem.getChildren()));
				childrenList.add(node);
			}
		}
		
		return childrenList;
	}
...

          private class MenuTreeitemRenderer implements TreeitemRenderer, Serializable{

		/**
		 * 
		 */
		private static final long serialVersionUID = 1L;

		@Override
		public void render(Treeitem item, Object data) throws Exception {
			DefaultTreeNode node = (DefaultTreeNode)data;
			MenuItem menuItem = (MenuItem)node.getData();
			item.setOpen(false);
			//item.setLabel(CommonFns.getLabel(menuItem.getLabel()));
			item.setLabel(menuItem.getLabel());
			item.setImage(menuItem.getIcon());
			item.setValue(menuItem);
		}		
	}

public class MenuItem implements Serializable {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	
	static int ROOT_ID = 0;
	private UUID id;
	private String label;
	private String icon;
	private String file;
	private String title;
	private MenuItem parent;
	private List<MenuItem> children = new ArrayList<MenuItem>();
	
	public MenuItem(UUID id, String label, String title, String icon, String file, List<MenuItem> children, MenuItem parent){
		this.id = id;
		this.label = label;
		this.setTitle(title);
		this.icon = icon;
		this.file = file;
		if(children != null){
			this.children = children;
		}
		this.parent = parent;
	}
	
	public MenuItem(UUID id, String label, String title, String icon, String file, List<MenuItem> children){
		this.id = id;
		this.label = label;
		this.setTitle(title);
		this.icon = icon;
		this.file = file;
		if(children != null){
			this.children = children;
		}
	}
	
	public MenuItem(UUID uuid, String label, String title, String icon, String file){
		this(uuid, label, title, icon, file, null);
	}
	public UUID getId() {
		return id;
	}
	public void setId(UUID id) {
		this.id = id;
	}
	public String getLabel() {
		return label;
	}
	public void setLabel(String label) {
		this.label = label;
	}
	public String getIcon() {
		return icon;
	}
	public void setIcon(String icon) {
		this.icon = icon;
	}
	public void setFile(String file) {
		this.file = file;
	}
	public String getFile() {
		return file;
	}
	
	public void setTitle(String title) {
		this.title = title;
	}

	public String getTitle() {
		return title;
	}

	public List<MenuItem> getChildren(){
		return children;
	}

	public boolean isCategory(){
		return !(children == null || children.size() == 0);
	}
	
	public void add(MenuItem item){
		children.add(item);
	}
	
	public boolean remove(MenuItem item){
		return children.remove(item);
	}

	public void setParent(MenuItem parent) {
		this.parent = parent;
	}

	public MenuItem getParent() {
		return parent;
	}
}

list content:
-MenuItem1
  -MenuItem1.1
  -MenuItem1.2
-MenuItem2
  -MenuItem2.1
  -MenuItem2.2

result in tree:
-MenuItem1
   -MenuItem1.1
-MenuItem2
   -MenuItem2.1