Well, I'm still favoring the polyline/spline theory. I think that you've got some curves in your mesh that don't belong there, and it looks like some non-planar polys or concave polys near that hole. You could bring it into UV Mapper to see the splines and find any bad polys. Just put view wireframe on and be sure to have show backfaces ON also. Go to Select>Select Facets>Degenerate and then hit TAB to see the 3D view - rotate the model if you have splines they will show up as lines without any surfaces. Anyway good luck - this one is a toughie.