Problems with PNG Tree Leaves + Diffuse

[bickel.sg]

Hello,

I have been trying for several hours to get some trees from the sketchup warehouse to render correctly. They are supposed to be VRay ready, but look like the following:
Attached are also the diffuse settings I am using for the leaves.

[bickel.sg]

As a follow up, I looked in the temp texture file. Earlier when I imported the tree model from the 3D warehouse I had changed the diffuse color to green. It is saving this setting and forcing it as the alpha color. Is there any way to change it back?

If I delete the diffuse layer and reinstate it, the green will appear but after changing it back to black/white it does not affect the render.

[bickel.sg]

I figured out that I didn't have an alpha mask on the transparency layer. Sorry to waste everyone's time.