Thank you. That worked.
I had read issue 272 before, but my incompetence with git let me down. I got it right this time.
What had put me off the scent though, was that with the g2v9k test build I did, I got zero response on the native port or the programming port for that matter. I guess the two ports on the Due confuses things.
Anyway, back on track now.
Thanks again.