[away3d] PhongColorMat and RoundedCube

[sibhod]

I've been doing some texts with away3d's lighting and shading,
specifically PhongColorMaterial. I've tried applying it to a
RoundedCube, but it only seems to affect three of the cube's faces.
I've uploaded an example here:

http://sibhod.com/sandbox/phongRoundBox/
( click the stage to change the rotation axis )

The demo has 2 cubes, one applys a CubeMaterialsData with unique
PhongColorMaterial for every face, and one cube with a universal
PhongColorMaterial. It seems to only affect the lighting on three of
the faces.

The cube's materials are set like so:

                _cubeMaterials = new CubeMaterialsData({
                top:   new PhongColorMaterial(0x89A34E),
                bottom:new PhongColorMaterial(0x78613D),
                right: new PhongColorMaterial(0xFC1559),
                front: new PhongColorMaterial(0x9EC482),
                back:  new PhongColorMaterial(0xE3D394),
                left:  new PhongColorMaterial(0xA0F0E8)
                })

                _cube = new RoundedCube({
                faces:_cubeMaterials,
                width: 150,
                height: 150,
                depth: 150,
                radius: 50,
                subdivision:2 });

                _cube2 = new RoundedCube({
                material: new PhongColorMaterial(0x888888),
                width: 150,
                height: 150,
                depth: 150,
                radius: 50,
                subdivision:2 });

What do I need to do to have all the faces responding to the light
source?