Cannot reproduce issue as described.
Used data from here: http://www.mapcruzin.com/download-shapefile/so-america-railways-shape.zip
Set Region and Language format to Portuguese (Brazil).
Made KML with both a scale and no scale, in both cases the exact same KML file was created and displays fine in KML viewers.
Note that the exact same KML file also gets created when the region is english (US)