Personaly I would'nt get too hung up on the figures as long as the car feels good then happy days - just enjoy it.

Remember the figures shown relate specificaly to that set of rollers on a given day with a specific set of circumstances, gear ran, diameter of rollers,ACT temps etc etc.
Whether one set of rollers reads right or wrong whether they are higher or lower than another is neither here nor there really - you just can't compair with any degree of accuracy one set of power figures with power figures from another rr'd.