I tried using the important parts of the example from the SDK(Shadow Volume), but whenever I make a call to clear the stencil buffer I always get what was previously rendered from the last backbuffer. What could possibly be causing this?

I've tried that. I'll try to be more specific. When I make a standard call to clear the backbuffer, and z-buffer I get a black background. When I add to clear the stencil buffer I get a background that was what the previous backbuffer contained. It works like this for anything. I can run the demo on the SDK, quit at any given time, and start up my program and see the plane with its shadow volume on the screen along with the graphics I put in my program. It's too weird, and one of those unexplained mysteries to me.

Can you show the clear call you are using??
Steele.

There is a link to the source on that article; that should show you what to do to clear the scene.

Jack, great article by the way and congrats on the MVP awared. Did you by any chance write a similar article on using vertex shaders for the shadow volume. i have an implementation working of both CPU and GPU and while the GPU is faster it looses all its benefits for me when i try and incorporate vetex changing animation (such as skinning, or deforming my terain ;)) as the degenerative quads require updating independently of the other vertices, and then the normals need recalculating etc, making it much slower. I also read that CPU implementation scales better with large amounts of geometry due to the extra vertices pushed through the pipeline with vertex shaders; do you think this still holds true with the latest generation of GPUs?