You can drag and drop subfolders, and in the the url for italian you will see 'In arrivo' instead of 'Inbox' and this cause a 404 error so I take the label for the folder using var transInbox = ZmMsg.inbox; and replace it, this way it works for all languages.
Ok I'll wait a bi for other suggestions and then I will add chats.
Thank you for vote and suggestions, if you like you can vote for this bug
Bug 21818 - Error 404 exporting contact after translation too because is similar to the on for wich I added the code.
Bye