A customer has an anonymous FTP site with directory listing turned off in folders that are open for uploading. This enables GPG encrypted files to be placed in an upload folder, such that they are not visible to anyone but an administrator.
Using a command line FTP client (such as ncftp), with knowledge of the exact filename in the upload folder, you can download the file, even though it will not show up in a directory listing of the upload folder. This is useful for giving third parties access to certain named files without advertising the entire directory listing to anyone who connects anonymously.
Cyberduck does not appear to be able to download named files from directories that have directory listing turned off. This would be a very useful feature for customers like mine.
I attempted exactly what was suggested with no success. I attached screen shots as proof. I am able to download a file using a command line FTP client. I cannot do the same with cyberduck. You can try it yourself by attempting to download ftp://ftp.idmserv.com/incoming13/alextest
Note that the incoming13 directory has dir listing turned off. I believe this is what is confusing Cyberduck.