Hey all,
The mystery solved itself today with an email from Expedia, containing the following info:
Hong Kong to Melbourne
Flight Change Details
Monday, 21/05/2012
Qantas Airways Flight Number: QF30
From: (HKG) Hong Kong, Hong Kong Depart: 18:55
To: (MEL) Melbourne MEL VI, Australia Arrive: 05:55 07:10 (change) +1 day
Status: CONFIRMED Class: Economy
Aircraft: Airbus A330 Jet Seats:
It seems that QF30 has been changed to an A330 and will now take an extra 1 hour 20 minutes to make the journey from HKG. Presumably this reflects a change to the QF30 schedule out of LHR.
Thanks for your advice all :-)