I think one of keys is you must have an e-Passport (with the embedded chip) to use the Australian SmartGate system. I just renewed my passport last year before we went thru Global Entry application, so mine has it. But my husband's does not - it was issued in 2006, just before they started issuing all e-Passports in 2007.
But I'm sure Ngaire has the e-Passport, so that's certainly not the only variable. Sounds like they are still working out some kinks in the process.
