3D Problems

I want to move the projection center of my SWF to the middle of the screen. So in my document class I put:

root.transform.perspectiveProjection.projectionCenter = new Point(600,400);

I’ve also tried

this.transform.perspectiveProjection.projectionCenter = new Point(600,400);

and

stage.transform.perspectiveProjection.projectionCenter = new Point(600,400);

None of these lines seems to do anything, no matter what value I set for the projectionCenter. Does anyone know where I’m going wrong? I’ve read a lot of short tutorials and articles about 3D in Flash CS4, but for some reason their code is just not working for me.

Also, I am using Flash CS4 Professional and I am publishing in Flash Player 10

Thanks.