One thing I have not seen addressed (although unless it was in the last 10 minutes I may not have remembered it), is about the vent hole in the regulator cover. In some cases turbulence will cause the ambient air to differ due to the plane's attitude, and affect the air the regulator "sees". Although I have not had the problem, I understand that some have soldered a tube over the hole in the cover and run some silicone tubing into the fuselage where there is no wonky air. Just a thought, I hope your issues go away soon.