Vray Physical Camera + Backburner = ?

[Dellow]

Hi.

I'm a newbie on this forum, but I think you can help me.

I have the problem with backburner and Vray physical camera: all images, rendering with backburner are more dark, than if I render them myself, without net rendering.

for example:

 

this is render without using backburner: first attachment

 

and this is WITH backburner: second one

 

 

I've already tried different settings of gamma correction in customize. nothing changed. Also problem is only with Vray Physical Camera. Standart 3d max camera rendering correctly in both cases.

Sorry for bad English.