Yars ago on the Smith Micro forum there was a discussion about splitting faces.  Part of the problem is the order in which the faces are read.  The other part has to do with smooth polygons.  Smooth polygons is only meant for figures as in people and animals.  Not for hard surfaces that only bend in one direction.

Poser 5, 6, 7, 8, Poser Pro 9 (2012), 10 (2014), 11, 12, 13