Draw order issue (Transparency?)

Hello, please take a look at this:

(click for larger view)

I have 3 objects: a planet and two ships.

The planet is far away (z=4000) and my ship is the nearest one from the camera.

The problem is, the other ship is showing behind the planet and on top of my ship. What I would expect would be the ship to appear on top of the planet and my own ship on top of the other ship.

Anyone knows what’s my problem?

if things appear in the wrong order, you are missing a ZBufferState

I am already using a ZBufferState:

// create a Z-Buffer for the Scene
        ZBufferState z = disp.getRenderer().createZBufferState();

a missing updateRenderState() after attaching something to the scene?