There is also a selection box, I've screenshot-ed it in the Fb messenger chat.
Just below "move up" and "move down" is a box which allows you to select a scrap, I always choose to move it to the end of the scrap. I think if you choose the start it ends up not being in the scrap at all! (And hence not drawn).
Once you've picked it, just hit "move to". (Doh! Just realised this is exaaactly what swallowneck rote, back2skool Gott)
Or a useful reminder, the whole document is just a text file, as long as you know what your moving, just open it using a text editor like notepad instead of the therion view, and shift it there.
This is very useful to know if you need to change the scaling of the scraps to be the same.