In PW Stitch cubic, [in top tool bar find icon sphere->cube]  modify the nadir in Photoshop, then convert cube back to rectangle.

Dave

Take the camera off the tripod remove the tripod from the location, mimic the camera position and shoot hand held. Use matching stitching point in Panoweaver 4 to stitch the bottom shot in. Camera position should be at the same height and in the same position as the "last" rotational shot.

Regards, Smooth