using camera.Render() to render to a RenderTexture is not depth testing?

I am using code similar to the sample code in the documentation to render a Camera to a RenderTexture. It all works except it looks like the rendering is created without depth testing. All the rendered objects are rendered in a weird depth ordering as if depth testing was off. Has anyone else encountered this? Am I missing dome setting somewhere? I am using 24 for the depth buffer bits for the render texture.

Thanks,

MC