datruth, I would say no, I trade Canadian stocks all the time, all that is required is to buy the currency in which you'd like to buy these foreign stocks. So, in my case I bought Canadian Currency with my US Currency, and IB keeps track of this for me.
It's pretty slick, when I got to buy a stock on the Venture or TSX, it automagically knows to use my CDN reserves. I would think Aussie would be the same.
Steel