I tested the excellent instructions about how to copy your live site to a test site found here:
http://drupal.org/upgrade/copying-your-site-via-GUI
(Everything worked, although I discovered that the (undocumented) last step is to sign in to your admin panel and re-select your formerly-default theme on the new site.)
My live site is in the root folder, and the photos embedded in pages have links a href links like this:
/files/u1/photo_of_people.jpg
But my copied installation on a different web host shows broken images for these images. I viewed the properties of one of these broken images and discovered the new path to the images is:
/test_site/files/u1/photo_of_people.jpg
(The "test_site" is the name of the subfolder on that new copied version of my Drupal site.)
I thought I could solve this problem by changing the settings in Administer -- Site configuration -- File system. So changed the "File system path" value from "files" to "../test_site/files". But, upon further thought, I realized that won't make any difference for previously created A HREF paths. I also thought that its probably a bad idea to change settings in my parallel test site in case I ever need to use it to port over to the real site.
I now have come to realize that this path problem is related to the use of i18n on my site and the extra /en and /fr folders that preceed node names.