We finished beans yesterday and all fall the combine would not pick up the 30 ft. flex head properly. It seemed to work OK when running in the field in auto header mode but when you get to the end it would barely pick up. Also would not lift off the header wagon. Opened the rate of raise screw on the valve block no change. Switched to the 6 row corn head today. It picks it up fine. What gives? They weigh similar don't they?