We translate Drupal nodes in multiple languages at once. We use the module In-place translation ([url removed, login to view]). With this module, in the node edit form, you get the fields you wish to edit combined in the available languages and the module save the reelvant tnid nodes at once.
As the module description explains, this works fine for title and body fields, but for cck fields is not implemented yet (listed in the code as to do).
For cck filefield we see the field in mulitple languages. Both fields display now the same value, but there should be another file for each language available.
We would like to see a patch for this module to have support for CCK filefield.