Thanks, Andrew.
"You can do the old export/import routine, it works quite well."
To do this, do I need to be sure that "automatically write changes into XMP" is checked "on" in the catalog settings preferences?
Also, when I delete a file from one database, and then import that database into the second, I've noticed that the "deleted" file is still present in the second database, although it is removed from the first. Are there some actions that are not updatable using import/export?
Thanks again.