Wow, Bruce. Fast reply!
Yes, I have tried the uncheck / save / reset of Visual Editor. Did so again just now.
There's only one user: me.
Yup, I printed out the instructions and followed them step-by-step.
There are a lot of posts at Wordpress on this issue, and only a handful of people have been able to solve it. None of their fixes have worked for me, so far.
Regards,
Sheila