DOCBOOK-APPS: MS XML

I have been trying to get XML-spy 3 to work with Norm's XSL stylesheets, but
without much success. Then recalled reading somewhere that those stylesheets
might not work with Micro$ofts XSL engine.
Is it true that Norm's XSL stylesheets don't work with the MS XSL engine?

Regards,
Daniel Beukers