Make ball transparent but visible behind?

Hey I know it sounds easy, I did flipped the normals inwards and not outwards but it seems the render still are pointing out?
Is it bug or what?

I want the balls to be visible but the background of the ball to be visible. It means I have to flipped the normals invert. But it doesnt respond?

Set the outer ball to single sided. Blender makes objects double sided by default. This should work.

EDIT: Okay so it doesn’t work with BI at least in 2.54 which is strange since this does work with all of the GL shading methods in the 3D viewport and in the BGE, so this is possibly a bug in BI ignoring the normals.