DirectX, help!!! How an Ortho W-Friendly Projection Matrix must look???

Hi:
When I activate a W Buffer with a GeForce using a perspective projection matrix the results I get reading W buffer are OK, but in the case of Orthogonal projection it fails. I am afraid that it is due to the fact that my ortho projection matrix is not compliant but I can not find How an Ortho W-Friendly Projection Matrix must look.
Thanks in advance

I don’t why it is doing that, from what I know an ortho projection doesn’t need a w-buffer since the z values are equally spread from the near and far plane.

The W-buffer is only useful for perspective because it gives you a more equal spreading in the z values

And you posted this in the OpenGL Forum because…???

I thought that was obvious LordKronos… must be just me then…