I thought I had it figured out... then I added a bunch more variables and noticed that a whole set of variables that had auto-corrected had gone back to "as-typed" (which implies some kind of "history tracking" or something that I'm not at all comfortable with - I don't need surprises in the middle of coding). So I've given up the idea of using this "technique" as a check that the variable has been typed correctly (too bad, I thought it was pretty good).

I can't say that I know for sure that this was supposed to be a valid "feature" of the editor. It's more than a little irritating when development tools do what they want, when they want.