Always use matching fields. Otherwise, you may very likely get data imported into completely wrong fields with chaos as the result.
The script shouldn't automatically change to "last order" if you use the "no dialog" option.
For More Information on the dangers of Importing records when a table definition has been modified, see: Data loss bug : Spontaneous and erroneous import matching of new fields in specified imports !
This is one of many acknowledged bugs that can be found in the Known Bug List here in the Report an Issue section of the forum.
It can also be downloaded as a database file from: http://www.4shared.com/file/8orL8apk/FMP_Bugs.html
Thanks again Phil,
I have read the links regarding the bugs. I have noticed that when I add fields to a new version of my database, FMP automatically adds the fields to the import script.
I assume that this should not be a problem if the import is from an older version of the database that does not have the new fields, there will be not match. Even thought I have been checking the import script as I go...
If you can use matching field names, there is no problem as FileMaker will match fields by name for you and this will adjust for added field names.
If you add a field and you are unable to use the matching field names option, then the fields in the field mapping misalign and chaos happens unless you also update the Import Records Script Step. This is why I try never to use scripted imports unless I can also use matching field names. That's not always possible, but it's much safer if you can.
Some developers avoid using Import Records altogether to avoid experiencing this potential catastrophe.