I finally found the OGLAlphaTrans node and placed it in the render tree after the TextureMap node and before the NormalMap node.
Unfortunately, the mesh in the realtime preview just flickers as I orbit around it in the viewport. Also, the ambient occlusion and normal maps that were showing on the mesh before now do not show at all even though they are still in the render tree.
For the alpha image I exported a Targa file from Photoshop using black to block out the areas of the mesh that I did not want to show up.
I have updated my video card driver.
I have toyed with every checkbox and drop down listbox in the OpenGL material's properties (especially the ones listed under OGLAlphaTrans section).
My video card is a NVIDIA GeForce 7100 GS. Operating system is Windows XP. I am using XSI 6.5 Essentials.
Do I have the OGLAlphaTrans in the best place? Here (http://www.flickr.com/photos/10263769@N02/2581652779/) is an image of the render tree from the scene. Is this a known issue?