Placing a cutting plane with precision can be tricky.
1: Select [not marquee] the elements key to the placement of the cutting plane, make a 3D view of these elements and THEN open the Cutting Plane window gives a closer view.
2: Placing small free-floating elements outside the model will provide cutting plane reference points. Once the plane is placed, they can be deleted.
3: The Cutting Plane dialog window CAN be stretched to make the windows bigger.
Dwight Atkinson