matte shadow brightness (or color) bug with DR or backburner

[RSF]

Hello.

Shadow brightness or color other than 1 and pure black don't work with DR nor backburner.

It only works on an opened scene and without DR.
Even when renderering with backburner in the same computer doesn't work.

A attached the scene and renders done with DR.
In the first image I changed color to a dark grey in the second brightness to 0.5

Is this a bug?

Thanks

[RSF]

ok...it works using VrayMtlWrapper but not as object properties