This customer notified me today that the default Joomla template was what was showing on their site
On investigation, the default template had been made Beez2, and I think that this chnage was made when Hikashop were working on the site.
Rectified now (the correct template was applied to some areas of the site)
So - as before, I think the change recently made above now means that shipping is charged on items like freight free mp3 downloads
My opinion is that the easiest way to solve this is to sanitise the Postcode field so that when an Australian destination is chosen that the field can only have 4 digits between 0000 and 9999 (or even narrower as Au postcodes start at 1xxx and go to 8xxx I think)
That then removes the potential for not triggering the Auspost plugin when it is needed.