Pin tool is not working

Hi, Thanks for your reply, actually, this is the first time I'm writing to such a forum and so I really appreciate your time. 

Actually, since I wrote that message I realise it is not an issue of pinning. It's something else that I'm missing. 

To test our my rig I have been looking at the "Rin" character from the home page of Ch. She has a torso and head that moves in the way I want so I've replicated the rigging exactly but my character's torso still floats - it is not fixed to the bottom of the screen like Rin is. So then I used the "edit original" function and swapped out Rin's original content for my content (and deleted unwanted layers). This works very well - my character's torso is now fixed. However, if I save "Rin" as a new file and open this a s a new puppet in Ch it reverts back to the original problem - the torso is not fixed to the bottom of the screen.

Have you any ideas what I am missing?