I am surprised how long this question has been up and no reply was given. Well, without being an expert but having experience due to owning a 1968 182, I can tell you that it is pretty much the way it is. However, I do not think it is because of the valve position as much as the way the tanks are vented. On my airplane fuel travels from right to left and if its only me on board and light on fuel, most of it is goes to the left and the airplane banks that way inevitably. what I do to remedy it is select the fuel valve to the right when the airplane is in the hangar and try to keep it from getting to low. either way, it seems that this is quite common on early cessna high wings...