Ah, in fact it hadn't written to any of the three files it's meant to
change when you click Apply Changes. I had to give additional write
permissions (and created the additional backups myself just in case).
Backups still weren't created tho, presumably because it doesn't have
write permission within the directory. I feel that if it fails to
create backups it should not apply the changes, or at least warn you
and ask for an additional click (telling you to make backups
yourself).
However, it is all working now, so I'm happy! :)
Thanks for a great extension. Looking forward to the jquery version...
Stu