Had a similar problem when I was assembling my Here Be Dragons pic. I had assembled a group of 2 characters with clothes in a specific pose. Saved the group off into a library, offset the original group, and then re-imported the saved group to verify it saved correctly. All was okay, both groupings were identical. Got distracted with tweaking the original group, and suddenly this happened. I thought it was an aberrant point-of-view distortion, but when I tried (as an experiment) to export the distorted group as an OBJ and open it in another program, the distortion was still there. Weird. Never figured what caused it, but next time I started poser and loaded the group, I couldn't get it to re-occur.