Render mask with opacitymap not working.

Hi,
is there a known issue with opacity maps and render mask?

If I render a specific object with render mask (selected, layer etc) it includes objects behind the selected object in the alphachannel.
Simple example: A leaf. An black and white opacitymap of a leaf on a plane.
In the part of the leaf that was supposed to render transparent I can se the background.

Probably an easy solution but I can’t seem to find it.

Could this be your solution. Render Mask - Selected - Issues - Chaos Forum