Oh god that happens to me too!!!! I just tested it. I didn't realize. Is it that much of a problem? My biggest complaint with google is if you type words in it brings up anything with those words in it and I'm of clicking on things that turn out to have nothing to do with what I'm looking for.
I tried 'preferences' and theres no boxes to tick or change anything. Maybe if you're in Australia thats just how it goes! Its still google, and you get the same search results.