The problem might be the FTP client mode you're using with your FTP client. The command line FTP application uses standard mode FTP (also referred to as 'port' mode). If your FTP client is trying to use PASV (also referred to as 'passive' mode) mode, the FTP site might not support passive. You can try changing the client so that it uses port mode and see if that makes a difference.
This was first published in June 2002