I and several other people have been having a different but similar problem in saving smart propped items to the library -- in my case, I use various wave deformers and sometimes get that weird "leftover" item -- annoys the heck out of me...

thou and I, my friend, can, in the most flunkey world, make, each of us, one non-flunkey, one hero, if we like: that will be two heroes to begin with. (Carlyle)