As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DEN - INFLIGHT JFK-SFO. CREW REPORTED FLIGHT DECK O2 PRESSURE DROPPING DURING FLIGHT. FLIGHT DIVERTED DEN LANDED WITHOUT INCIDENT. CAPTAINS O2 MASK FOUND TO BE LEAKING. REPLACED CAPTAINS O2 MASK WITH 2ND OBSERVERS MASK AND PLACARD 2ND OBSERVERS SEAT INOPERATIVE PER MEL 25-19D AUTH 1103-C. REPLACED SECOND OBSERVERS O2 MASK AT SFO ON 03/25/2011. SYSTEM GROUND CHECK NORMAL OPERATION.