I have just looked at the Air Asia web site and have seen that my flight booked for next week is departing an hour earlier than the time that is on my booking ticket. I called them and was told yes it is departing at the earlier time. I did register with them and did not receive an email advising of this. I presume due to being no frills that they don't do this.
Just thought I'd let anyone know who is flying with them soon so you can check your departure time. Lucky I did or we would have arrived too late for check in!!