I can think of three possible options:
1) Serious bug in TBC that prevents the Report from displaying data. I believe German version of TBC was affected recently.
2) Not-so-serious bug in TBC. Your boundary has overlapping segments and/or doubled up vertices. Use CAD -> Detect Crossing Geometry on you boundary polygon.
3) Your two surfaces have only 5.4 square feet in common within border polygon, and those 5.4 square feet are at the same level, hence the depth is shown as 0.000ft.
------------------------------
Marian
------------------------------