I'm looking at BNE-LAX fares for next week, and noticed something odd. I have the choice of Sale, Saver and Flex on both legs. If I choose Saver on QF16, every single other fare option across every single flight (and there are 16 of them - direct, via SYD, MEL etc) is greyed out. I understand usually it will do that to stop incompatible fare selections - but all of them? Within the Saver class are some buckets not allowed to be priced togeher? Seems very strange.