No bumpmap through transparency?

So I have a leaf, with transparency around it, you know, to cut down on polys. It’s just a plane with a leaf texture and transparency, and I have my tree bark, with uvmapped textures and bumpmaps etc… however… when my leaf is in front of the tree, you can see where the square is, because the bumpmapping goes away just where its transparent… why is this?

Is this happening in the real-time preview or is it happening in the render?

Also, it would be helpful for you to post up a screenshot showing your problem, as I can imagine this isn’t an easy effect to describe.

I think(not sure) that can be resolved using z transparency for the leaf plane.
Are you ray tracing it ?