I have had SWU problems twice this year. Once at Burbank on a BUR-SFO-HKG-SIN flight when the check-in agent asked me how I was going to support my upgrade. I explained that the upgrade was confirmed months ago and the SWU was pulled from my account at the time of booking when the upgrade cleared. When I got to SIN, I found an extra SWU was pulled from my account. The second time was HKG-SFO-LAX on a sponsored SWU. The check-in agent at HKG insisted that there was no SWU to sponsor the upgrade and pulled another SWU from my account. Both times I got MP to return the SWUs after I returned to the States but if I didn't have extra SWUs in my account, I would have been downgraded to Y. Both times I complained to 1Kvoice and both times I was told that it was a computer glitch as they can see clearly on my record that the upgrades were supported.