Overlay quads on a video

Should be simple… but I can t get it.
I have a set of quads with a halo (png) texture, they go to a render for further fxing and back to quad, I then overlay this quad to a video from a web camera but I can t get right the blending with the video and the colored quads, they overlayed quad is transparent where black (as it should) but also semi-transparent where the color is, but it shouldn t.
I tried different settings with Alphatest, Blend and the pre-fx renderer´s texture format but without getting a proper result.

patch!.. no text …

Overlaytest.v4p (19.3 kB)

Related to this?

(hint: alpha color of the renderer you take the texture from)

Thanks! … no text …