Hi - We're in brisbane and I've had all series from Amazon UK and they play fine. However, we had a buy a new DVD that plays all areas. We just got a cheap one to supplement our more expensive, region 4 only player.
You know I bought region 4 dvds when visiting Australia, and they plays on my region 2 dvd-players. I think that as long as it's not NTSC it will play on Australian dvd-players - but I'm not a 100 % certain.