In Reply to: Passport Question posted by iguanabw on Sunday, 8. February 2009 at 14:54 Bali Time:
If you dig around in their FAQs they advise you to enter you expired passport number if you have not yet applied for or recieved a new one. Once you recieve the new one, you contact their guest centre (check site for 1300 number) They may the ask you to scan a copy of the new passport and email it to them for confirmation.
Once this is done they will email your itinerary with updated passport numbers.
I have done this (booked flights for people who don't currently have and have never had a passport) via the air asia web site. The guest centre advises that there may be a bit of a wait when calling their 1300 number until their centre is improved on Feb 15 this year.