shadow stitchling problems


I’m rendering a scene with planar reflections and planar geometric shadows. The reflection is perfect and the shadows projected in the plane are good but have undesirable effects(flickering). I think it’s a problem of polygon offset solution, but I tried many things without success.
Note: I’m using blending for rendering the shadows and a reflection of same object.

Thanks in advance,

I got it! If someone is interested in know how avoiding z-buffer problems when rendering shadows (using stencil buffers) I must tell that I solved the problem using the next OpenGL commands:
(note: all shadows must be rendered into stencil buffer region specified by 1)


Thanks to all people would read the mail,