ROTATING A CUBE IN 3D SPACE

Hello,

I've created my first 3D cube in AE and I am trying to manipulate it in 3d space.

I've created a null object and made it the parent of all six faces.

Everything works fine, except for one thing.

When I change the value of the X-setting on my null object, the cube rotates vertically rather than horizontally.  That seems to be the opposite of what I would expect.

Any thoughts on that?

Here are two screen shots that illustrate my dilemma.

Thanks!  

Matt