I don't think it has anything to do with smoothing groups. I imported the Poser 6 bra into and re-exported it, without export smoothing groups set in Habaware, with exactly the same result, as you can see. I also had it set to export as triangles, that didn't make any difference, either. I also ran my own swimsuit, which never had smoothing set anyway, through Poser 5 with no change in the results. I think the problem is very simple, there is a bug in Poser 6 that should have been fixed, but went unnoticed. It doesn't weld polygons if they are in parts that aren't continous with the main split.