weird spotlights

When I render an image from a spotlight and then put the rendered image as a texture for the same spotlight (“view” selected at the texture mapping options) the image doesn’t align perfectly with the scene.

for an example of what the problem is see the link

http://members.lycos.co.uk/kurppa/QAs/spotprob.htm

any suggestions on how to make the damn thing work?

(tried to do this an other way with the method that was used in the old ParticleSystemShaddows-tutorial but that’s no good)

any help would be appreciated.