Spell checkers look for something in their dictionary that's close to what you've entered so far. I *suspect* it's done partially through phoneme matching, where the spelling of /ph/ gets mapped to the sound of /f/. It's giving you everything that's close.
So what you really want, I suspect, is a better dictionary, not a better spell checker.
Hmmm... after checking "Variol" in my spellchecker in FF, it came up with nothing starting with "var", and focused just on the "ario" in the middle. Maybe you *do* need a better spellchecker too..
