Welcome to FileMaker. Two possibilities right off the top of my head:
1) These files are being hosted by FileMaker Server? If so, then by closing the source database, you'll be restoring "all records" in the source table when it's automatically opened by the Import step.
2) If the Find request in the source database fails, then all records in the source table will be found.
Suggestion: Get rid of the Close step in your Otto_go script. Leave the source database open. This will retain whatever found set you have during the import. You can close it after. Also, make sure you put an error trap in there to catch the case when no records are found.
Thank-you. That worked perfectly.