Changing screen resolution will change the size of the screens designed in Intelli-Site which will change the look and location of the screens on the monitor.  It can change it enough that parts of the screens or even all of the screens are not on the visible portion of the monitor.  Therefore, it is important to design the screens in Intelli-Site at the resolution needed ultimately.  Otherwise, when the resolution is changed, all of the screens will need to be modified to fit the new resolution.