Hi Penny,
When restoring a Moodle backup file to Moodle on a different server than the one used to create the backup, the absolute referenced links to files maybe broken.
To fix this problem open the backup-coursename.zip file and edit the moodle.xml file replacing links with $@FILEPHP@$.
For example, replace http://yourserver.com/file.php/243/ with $@FILEPHP@$
When the file is restored it will use the correct file path for the new course.