Slowly getting the hang of Blender, now having issues getting the results into Poser.

Created a nice profiled piece, rendered in Blender just fine (in both Blender Render and Cycles), exported as .obj.

I've figured the correct export scales and such to bring it in to Poser properly scaled and oriented, but I'm getting ghost edges in places that get filled by the materials. It's like the material is being placed on something that isn't there.

The image below shows the profile as wireframe and as it appears in the preview window (renders the same), with the offending additions circled...

any clues as to what is happening? I've tried exporting with default settings, all sorts of variations both on export and import and always the same.

Cheers.