Unfortunately, I realized that some problem when using JME and FengGUI!
Can't see FengGUI when you use setRenderQueueMode(Renderer.QUEUE_OPAQUE). How to solve this problem!
Scratching my head!
See example: class IngameGameState extends CameraGameStateDefaultCamera
and add following line:
b.setRenderQueueMode(Renderer.QUEUE_OPAQUE);
why do you want/need to set it to opaque ?