title: YUI MenuButton: menu doesn't show when menu widget is added to button widget
body: <p>Using YUI, I want to create a menu button, passing in the menu widget instance.</p>
  
  <p>Result is what looks like a menu button, but the menu doesn't show.</p>
  
  <p>test case: <a href="http://sandbox.kluger.com/menu_test.html" rel="nofollow noreferrer">http://sandbox.kluger.com/menu_test.html</a></p>
  
  <pre><code>// key code section:
      var D = YAHOO.util.Dom,
          menu = new YAHOO.widget.Menu(D.generateId(), {lazyload: true});
  
      menu.addItems(params.menu);
  
      var t = new YAHOO.widget.Button({
                  type: "menu",
                 label: params.label,
                  menu: menu,
             container: el
      });
  </code></pre>
  
  <p>Do I need to render the menu before giving it to the Button? </p>
  
  <p>If you want to see the params.menu, check the test case. The params.menu object is correct, it creates a menu when directly supplied to widget.Button. That's tested in the test case.</p>
  
  <p>Any ideas appreciated.</p>