I can confirm that my first case is fixed.
But I see something strange happening in the seconds (unless my laptop/linux is pulling my leg).
When I type somewhere in my existing file
The this works ok.
But when at type this at the end of my file (which has an empty line at the end (as required by the standard), the moment I have typed the
I get something strange :
and that DC3 is white characters on a black background.
I will reboot later on, and see if this remains.
EDIT : yes it does, so seems there is a side effect.