As a workaround while the IT boys are probably playing "Who's gonna tell the boss" and rapidly trying to propogate a DNS entry across the Internet:

The change that seems to have been made is the migration of booking services from the application server http://wftc3.e-travel.com/ to http://book.qantas.com.au/

When the booking fails, simply replace http://book.qantas.com.au/ in the URL bar with http://wftc3.e-travel.com/ and hit enter. Your search will load correctly.

Note this may go totally wrong for you. You take full and any responsibility for anything that goes wrong with the booking