Viewport.Magnify

For some reason I can't get the method:

to work in a C# component.

It looks like everything should be working fine. Is there a conflict between setting the camera location and then using magnify?

Here's the Code:


private void RunScript(Point3d cameraPoint, Point3d targetPoint, double magnificationFactor, ref object A)  {
    doc.Views.ActiveView.ActiveViewport.SetCameraLocations(targetPoint, cameraPoint);  
    doc.Views.ActiveView.ActiveViewport.Magnify(magnificationFactor, 0);  
    A = magnificationFactor;
  }

Thanks,

Ben