DesKam and DeskNC Users

I have downloaded the demo versions of DesKAM and DeskNC for evaluation.
I have come across a snag in DesKAM, or maybe it's something I don't
have set right, but, here's the problem.

I loaded into DesKAM a DXF file from AutoCAD of one of my wing ribs that
I designed. When I brought it up on the DesKAM screen, it shows the
shape of the rib as two straight lines (upper and lower surfaces), and
not the actual arc/curve shape it should have to the high point on the
rib from the front to the rear trailing edge.

Have I set something wrong, or not drawn the part correctly in the CAD
area, or is the part actually correct in the program, but looks
different on the screen?

I will try another part that I have designed, and see if that has
similar results.

Thanks,

Don Hughes