Dear Gordon,
That did the trick!
I made both the 1.9 Hot Pot Module version and the QuizPort version on my local server and then uploaded them to my online site and and all the links continued to work perfectly.
If anyone's interested in copies of my html files to use as templates, I'm happy to provide them. I think copying and modifying files is the quickest way to generate new exercises of this type (rather than regenerating from the Masher). The JMixes themselves have to be created in the usual way of course.
Thanks again to Gordon and Stan for this great adaptation.
Cheers,
Glenys