yafray might be easier to use in this case just try it and see what happen
yafray is a thru photon ray emulator which blender is not and has to use a lot of trick to do things like that - yafray is the champ from that point of view!~
If you don’t want reflections the simplest way to do this might be to select OnlyShadow under the materials property of the plane. This should mean that only the shadows on the plane are rendered, not the plane itself. Then go to the world tab and set the background colour to white, or however you want the background to look, and the shadow should be rendered straight on to the background.
DichotomyMatt, I did read that thread (it’s where I got the image), but they never did post the solution to the problem! So I figured I’d try again. However, it would be helpful to know how to have a reflection as well, but my immediate needs don’t require it.
4jsquared the only shadow suggestion was exactly what I was looking for. Thank you!