[Zope] Editing SQL methods from Emacs (+ FTP server)?

All the texts explaining the wonders of Zope tell that you can edit your DTML files from (X)Emacs, and not from the lame editor you get from your browser with the default HTML form. It works great for DTML but ange-ftp (GNU emacs 20.7) refuses to open the SQL methods ("File exists but cannot be read"). Is there a solution, besides writing it offline and uploading it into Zope?