When I load the Terrain Assets package from the Unity webpage the one of 35 megs.
I insert the trees either by terrain painting or individually and they may look fine when I hit play sometimes
but when exporting and running a test on any export (web,pc,mac...) the ambient occlusion trees seem to glow
I've tried downloading the package again and tried on 2 computers and it happens the same.
I'm using Unity 3 free version.
I'm attaching a reference pic.