When the NetBeans IDE creates a popup menu with "New" submenu, the content of the New submenu is constructed as empty and is populated with correct items when PopupMenuListener.popupMenuWillBecomeVisible is called, which is registered to JMenu.getPopupMenu().

This worked OK until:
java version "1.6.0-rc"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.6.0-rc-b62)
Java HotSpot(TM) Client VM (build 1.6.0-rc-b62, mixed mode, sharing)

In this JDK build, when submenu is never shown, because the PopupMenuListener.popupMenuWillBecomeVisible is not called, and the menu is therefore never populated.

Please see the attached example, the Test menu contains one item on older builds, but contains no items on the above build.

This seems to be caused by fix of 4417601.