More SpellChecker quirks - Select default language or check in spanish anyone?

At the moment I'm just looking into an extremely interesting bug within the sharepoint spell checker. One of my colleagues, Fred  Schwass, informed me that when you type in certain words the default language drop down appears asking you to select a language (Australian in our case) even though  we have explicitly set to default to Australian anyway.

Normal functionality performs as follows. Enter your text, submit your form or check your text, spell checker highlights suggested words

Buggy functionality perfroms as follows: Enter your text, submit your form or check your text, spell checker requires you to select default language, spell checker highlights suggest words

It's funny because you type in "Innacurate" or "Orange tree" and it produces the bug however typing in "orange" or "tree" will not produce the bug. There are also certain words that trigger the spellchecker to check the words in spanish.