--- uc_edi.module	Mon Jan 05 17:23:27 2009
+++ uc_edi.module	Wed Feb 04 10:23:44 2009

-function uc_edi_archive_file($filename = '') {
-  $filename = variable_get('uc_edi_order_export_dir', '') .'/'. $filename;
-  if (file_move($filename, variable_get('uc_edi_order_export_archive_dir', ''))) {
+function uc_edi_archive_file($filename = ''){
+  $source = variable_get('uc_edi_order_export_dir', '') .'/'. $filename;
+  $destination = variable_get('uc_edi_order_export_archive_dir', '') . $filename;
+  if (rename($source, $destination)){
     drupal_set_message(t('Order EDI export file %file was archived successfully.', array('%file' => $filename)));
   }
   drupal_goto('admin/store/orders/edi/download');