I have found a bug.
i have two shipping methods setup - manual shipping method which is set to ship only to zone 'australia' and australia post shipping plugin which is set to ship to zone 'world' which i created that has all countries apart from australia set as its sub-zones.
Now when i am in the checkout and i have a shipping address for australia the flat rate manual shipping method displays which is correct. If i then create a new shipping address that is in another country other than australia, it works correctly and only displays the Australia Post method for shipping. But when i create another shipping address that is back in australia it does not revert back to the manual shipping method but stays on the australia post shipping plugin (which should not ship to australia).
hope you follow/understand what i mean