blending and transparency

im rendering a set of polygons, and no matter which polygon i render first, the transparency doesnt work on that polygon.

im rendering a cube from back to front using
GL_QUADS.
blending is GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA.
does anyone know why this is happening?
if you need more info ill be happy to give it.
-Dave

Code please.

  • With which values did you clear the color buffer?
  • When and which colors or materials do you assign?