Upload dir goes wrong when no 'file' dir exists

FileField module uploads files to drupal's file dir.
But a drupal-5 installation comes with no 'file' dir (until url admin/settings/file-system was first visited).
When a file dir does not exist, FileField uploads files to site's root dir, which leads to a reference error later.

Tested with
drupal-5.10, filefield-5.x-2.3, cck-5.x-1.7.