Everything seems to be working fine now. I discovered that it was a glossary within a course (id=10) that was being used to create dynalinks on the front page. When I got rid of that glossary all the dynalinks disappeared. What confused me was that the URL being displayed in the status bar, when I hovered on the dynalink, was using courseid=1.
Oh well, all sorted. And it's a fantastic function.
All the best,
Mark