Preview "right click" goes walkies for .txt

If I have a simple view with the Preview pane showing a .txt file, the "right click" fly out where I can change the view is nowhere near the preview pane. Indeed, if Opus is on my right-hand monitor, the popup is on the left monitor.

The popup for other file types is usually where it should be.

Hang on, it is also in the right place for some .txt files. The odd ones are email messages exported to .txt.

This behaviour is with the "default" preview handler. If I pick the "text" plugin it is as expected.

Anyone else see this decidedly odd behaviour?

How can I force the "text" plugin to handle all .txt files?

Ta.

Are they literally .txt files or are they text files with a different extension?

If they are .txt then you must have a preview handler that has assigned itself to that extension. You could disable it, or remove just that extension from it, using the ActiveX plugin config window, under Preferences -> Plugins -> Viewer Plugins.