I read one theory that places homoerectus in Australia prior to the arrival of 'moderns' 60k years ago and that the Aboroginies(sp) of today are the result of that meeting. (Ansestors of a combination of the two)
The problem is that erectus would have had to be able to navigate at least 50 miles in the open ocean for them to get there, and I don't think our scientists are willing to accept that yet.