you don't need to mod the app support file for 1.1.2, i myself have got my phone working perfectly on optus with 1.1.2 without touching that file. First you need to install iWorld from installer.app if you haven't allready, then open it and select australia from the list of countries. (this will fix the problem with text and phone apps not opening ) then go into settings>general>international and select australia as the region. It will then format everything as if it were and Australian iphone.