I'm not sure how this would work with props that have multiple children... I don't know if you can save more than one prop at a time as a prop... but this is what I would do, and granted, this is the long way around. First, parent all of the props to the parent, then save each child, and the parent prop by themselves, making sure that for each child, when Poser asks if you want to save as a smart prop, you choose yes. Then when you're reloading, load the parent prop first, then reload each child... the children should reparent themselves to the child.