overlapping polygons

i have one last problem with my shadows.
first i want to say, that my shadows are working completly except this tiny problem, and i want to thank you people for helping me with this.
now, my problem is simple, and i hope so is the solution. sometimes one of the shadow volume side overlaps the object itself, and wierd popings are seen on this polygon, and happans all the time with capping polygons of the volume, i.e the polygon that close the volume on the end closer to the light, they always overlaps the object, because these are the same polygons, jut renderd to the stencil. should i use polygon offseting, or another depth function?
im using GL_LESS, and i tried GL_LEQUAL
but it didnt work.

no one knows your the answer? i doubt that.
come on, some one must know.