Yes, Show Images in the Preferences Editor is set correctly.
This has been an issue since the moment I upgraded Opera and I am the only person using this computer.
I have changed no settings and no one has been near this computer to touch it.
I am also very careful about what I allow on this computer. No porn, no spyware, no warez at all. Nothing remotely questionable because I just don't want the hassle of dealing with it. I check it regularly to see what processes run in the background. The problem is coming from Opera itself and it's very frustrating.
Thanks, Pesala, for your attention and advice, though. And I would be grateful to hear from anyone else on this issue because if I don't fix it I'll just have to walk away from Opera, which I've been using for many years now.