I've also had an oxygen system-related problem. After using it for the first time it's now giving me an "oxygen fault" annunciation on the PFD which won't go away. I tried filling the O2 system from the maintenance page and cycling the appropriate fuse on the circuit breaker panel, without success. I found a reference to this specific annunciation in Garmin's Cirrus Perspective manual, but there's no explanation about what it signifies or how to fix it. Any thoughts? Thanks.