That's strange. If I comment out where that phrase is set in ckeditor.php, I'm missing the editor, so it looks like that error is related to the problem. However, when I press "Submit" I always just get the same thing again. I could understand if that phrase was missing, but I don't understand how it would only be missing sometimes.

When you get the page with the missing editor, do "View Page Source" (or whatever for the browser you're using) and search for wrap_x_tags. It should be there in the middle of a big bleck of included js code that starts with