Importing a site duplicates list items

[schambers]

When importing to a blank site, the import command:

STSADM -o import -url <url> -filename <file.cab> -includeusersecurity

works like a charm. The new site is identical to the old site and is
functional.
In doing data recovery scenarios, I deleted a folder from one of the
document libraries, then imported the site again, over the top of the new
site. This time I added "-updateversions 3" to the command so it would
ignore files that were already present. This too worked like a charm, but
only for the document libraries. All of the list (Links, Discussions,
Announcements, Calendars) items duplicated themselves.

Is there a way to prevent this from happening?