The trick is to work on the obj from the Geometries folder. These obj's are not split .. splitting occurs when you load the CR2 in Poser (or Phi file, if you used Phi Builder to create the hierarchy). Poser uses the Group details to separate the 'actors' (body parts) by splitting them along the seams. There's a very good tutorial by diviner here http://www.renderosity.com/mod/tutorial/index.php?tutorial_id=865 . It's for ZBrush > Poser, but should work for most modeling apps.