Are you referring to AutoCAD's bounding box or the red bounding box from kubit?
AutoCAD Bounding Box: In AutoCAD 2013, if the bounding box is showing with the cloud on screen you can use the command POINTCLOUDBOUNDARY and turn your setting to 0 . If "All Points" are turned off from the kubit section manager then the AutoCAD bounding box will always show. To completely hide the cloud and the bounding box, move the cloud to a new layer and turn the layer off.
kubit Section Manager: If the red or transparent box is showing, highlight the section in the section manager and click the top left button on the section manager called "Display style options for section markers." This will allow you to switch between transparent, wireframe or no bounding box. To quickly get rid of the bounding box, simply click in a blank white area of the section manager.