Not sure if this is a Vray issue or a Forest Pro issue, but I have 2 Forest Pro tree objects in a scene, one in front of the other. I have one of them set to not render reflections and the other to go ahead and render reflections. The one that is set to not render reflections is actually cutting its shape out of the ones that are set to render reflections. So in the reflection, I can see the sky cut out in the shape of the trees that aren't supposed to be reflecting. Sounds confusing, maybe the images will help.