If your camper is sitting level in the truck bed and your tie-downs are tight, then ignore the cabover movement....it means nothing....it is actually the cab of your truck moving slightly differently from your box due to frame flex.....if you look in your mirror at the camper in relation to the side of the box you will see that the camper is not moving in the box.....I have been carrying campers for over 25 years and pay no attention to the independant movement of camper and cab.....slowly drive diagonally over a speed bump and you will see how the truck frame torques and moves box and cab differently.....