I have two Garmin Oregon 750T units on which I cannot seem to calibrate the compass. When I bought the first unit, I frequently failed on the 3rd step (flip end over end) but after a couple-three tries I was usually able to get the last step to work. However, for the last 6 months or so I cannot ever get the 3rd step to succeed. I have tried, I have had others try, no luck. I am currently running version 5.90 on at least one unit and probably both. Also, every time I turn on the units, I have to calibrate otherwise the needle will point either 90 or 180 degrees from the actual tract. Any help/suggestions would be appreciated.