Ubercart 2.6 includes CIF files for *all* countries, including Brunei Darussalam. So this contribution is not needed and should not be used - the differences between this and the CIF in Ubercart will only cause confusion and result in support issues.

If you find problems with the CIF files in Ubercart, the proper way to report those issues and get them fixed is through the issue queue at http://drupal.org/project/issues/ubercart