Well, as you can see from my first posting I have now received a response from technical support at proDAD and I've just started to follow the recommended steps even though I did follow them previously, just in case I missed something as I really want to get this up and running.
To ensure that I was using EXACTLY the trial version recommended I uninstalled the original download and then downloded the version proDAD support had sent me the link to. I went through the installation process and, I'm sure you can guess...
Surprise surprise when I came to reinstall I am now asked to enter a serial number with no option to continue with the trial. I am now therefore further back than I was beforehand as I don't even have an evaluation copy to try to get to work.
I have a strong feeling this is going to be a failure :-(
Here is the relevant part of the email I was sent:
And install please this current version of Mercalli SAL: Click here.