tex3d lookup yields black mesh - why??

Hi there, I've been scouring every nook of the unity community, and other online resources, and have found no answer to why using Aras' example found [here][1] yields a black mesh. I'm running 4.1.3f3 on a new macbook pro (which was confirmed in the previous post to support the feature). Many others have had this problem, [like these folks][2], [and again here][3], but no one seems to have an answer. The docs have a broken link to what looks like is meant to be documentation on [texture3D][4], and I've successfully tested to see if `SystemInfo.supports3DTextures` yields "true", which it does. At this point I'm at my wit's end. If anyone has any leads on this, please share! Thanks, Lou [1]: http://forum.unity3d.com/threads/148605-Unity-4-3D-Textures-%28Volumes%29 [2]: http://forum.unity3d.com/threads/164556-Texture-3D-Problems [3]: http://answers.unity3d.com/questions/388482/unity-4-texture3d-problems.html?sort=oldest [4]: http://docs.unity3d.com/Documentation/Manual/class-Texture3D.html