Hello All,
I do once more apologize for my silly mistake about apparmor. As repentance, I have looked into all the issues Federico mention and solved the issue. In short, you have to create an apparmor profile for lilypond-wrapper.guile (it's not very hard to do - there are utilties to assist.)
I'll get all my thoughts in order and take down notes on how to do this, and update the Guide I wrote.
Here I was claiming it all worked fine and it turns out I had disabled the profile for evince and forgotten about it. I think I deserve a punishment. Perhaps I should be Transported to Australia for Life. Hold on, I am in Australia. :-)
Anyway, issue solved.
Andrew