What port are you logging into for web based FTP? You said you're using Cpanel to FTP? Can you explain what you mean by that? Are you logging into Cpanel and using their file manager, or are you talking about something else? Are you able to log in anonymously using an FTP program but your browser can't use ftp://ftp.hostname.com successfully? If so, is your browser configured to pass your email address or something similar for the login username?