A few dumb suggestions/questions:  Are guage wheel arms bent?  Are depth settings equal?  Did you drag the right end of the planter through a mudhole and pack the guage wheels full of what is now cement?  Are guage wheels set too tightly and getting caught all the way up?  Do the pins all have the same Cal Factor?  I'd also try as I think others have suggested -- swapping the RUMs between the rows and see where the problem stays as well as checking RUMs for pinched wires.  Have you reset your modules from the diagnose page lately?  Try going:  Setup -> Diagnose -> Device Status on the lower right had part of the screen --> then arrow down and see if the RUMs have the same voltage across the board.

Perhaps at the end of the day you would be happier disabling a couple of the pins just so you don't have to look at what you consider to be erroneous data.  AirForce needs 3 active pins to work in automatic mode...

That's all I got for now unless there's only one marker on the right end of the planter that weighs about 3 tons.