VrayLightMtl - opacity not working

There seems to be a bug in the VrayLightMtl.
I can’t get its opacity setting to work with a texture. No matter what I do, I get a 50% opacity on the entire plane I have mapped the material to. I have tried with both file textures and a checkerboard procedural.

I am running the snow leopard official 2.20.01 build in Maya 2012.

Try to make this object “invisible to camera”. The object will still emit light , but will be invisible.
Opacity parameter is working correctly - but it doesn’t produce this effect - the light is actually invisible - but the self illumination remains.
Try to render with opacity 0 % and 100% - and take a look into alpha channels of this renders !

Ah… I see, well that clears it up. It’s working well right now. Thanks for the help, Svetlozar.

Maybe a note should be made of this in the documentation. I’m sure a lot of people are using the VrayLightMtl to insert objects unaffected by lights/GI (like screen graphics or 2d text), and it’s certainly not very obvious to have to hide your object from render…