The auto spell checker and I don't always agree on how a word should be spelled. Also, it is apparently a British spell checker program, as it favors the British spelling on some words that Americans spell differently. I am American, and naturally use the American spelling. These disagreements mean I am always wrestling with the darn thing. I don't mind when it catches a typo, or a word that I am not absolutely sure how to spell correctly. But it catches so many other words that I am sure how to spell, or that are spelled differently based on whether one is British or American. I also have trouble sometimes with words I am not sure about. I will sometimes try several different spellings and still the spell checker won't like it, so I end up having to pick my own best guess and ignore the checker. You should be able to configure the language/country of your auto spell checker, not just the language you are using to access the web. It would also be good if you could add new words, or alternate spellings to an auto spell check dictionary--or for word wizards--a lexicon. 
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If a man does not keep pace with his companions, perhaps it is because he hears a different drummer.
Let him step to the music which he hears, however measured, or far away.--Henry David Thoreau