To stargold,

Just to clear up that it was my friend whose also a SO KrisFlyer Gold was being refused by the Qantas check-in agent to change his FF details for his last flight out of Australia to Singapore.

Additionally, as of I know a few SQ's local stations manager here in Australia as well as in some other Asian ports, many of them had told me that it pretty much depends on individual check-in agent, because many of them won't even bother to change the FF details for SQ paasengers (even elite ones!).

Best Regards.