What Release is your S8300? Some of the older Releases did not work very well. If you haev an S8300, that is an S-Series server.
Like I said, you need to use an external FTP server, for this to be effective. If you have access to a Windows 2003 server, and someone has installed IIS on it, that also usually installs the Microsoft FTP server. I have backed up S8300's to this FTP server, so I know it works. You can test it from a PC on your LAN, open a DOS prompt and type "FTP X.X.X.X" (where the X's are the IP address of your FTP server). Make sure you can log into in via anonymous/anonymous, and try to "put" a file, see if it works. You have to take things 1 step at a time, and verify it works from a PC first.. then try and get it working on thr S8300.
Mitch