how to connect scraps

I've been using xtherion to trace passage detail from my survey notes and now have a collection of scraps, each one corresponding to a page of my survey notebook. I have been unable to work out or find documented how I can connect up the lines for walls and such on adjacent scraps. At present I get a set of nearly-joined-up map segments when I compile the map from the set of scraps. Any help would be appreciated. Thanks, Simeon