What OSs are you using? Vista and Windows 7 can be picky on sharing and networks. Did you install the Smartware? How is this drive connected through the netwwork?
If the drive is connected to your network through a computer then in order to access it you will need to enter the username/password for the user account from the machine where the drive is connected to.
If that doe snot work then give us a little more info of your configuration.