Yes, albeit under different circumstances.

I was able to carefully plan and get 3 C and 1 F award tickets on SQ from India to SYD for later this year. Not all seats showed up at once, and I had to regularly check using the ANA website over a 2-3 weeks period.

Anyways, I had all 4 tickets issued, and decided to call SQ to make seat reservations. Two of the C tickets had been cancelled by UA, according to UA.

I called UA, and they confirmed it was cancelled by UA and not SQ, and they wondered if I had called in to cancel. Upon further investigation, I was told it happened due to some sort of computer error at UA(Funny how that would only happen on an award ticket).

UA has only been able to re-instate 1 award ticket in C. SQ is not confirming the other one anymore, and UA says there is nothing they can do.

They have credited an SWU to my account for my troubles.