Well, we can see if your Xbox is already correctly connected to your network.
Head to
FlashFXP's website and download the latest version of it. (You do not have to do this, but FlashFXP is one of the better FTP clients.)
Once download, hit f8. This will pull up a Quick Connect dialog box.
Fill in the server of IP area with the IP displayed on your Xbox, then fill in the user name and password with "xbox" (minus the quotes.)
If it connects, then you are good to go.
If not, it is most likely a small subnet error or your network is just a little different than everyone elses.
If you still have problems/questions, feel free to find me on AIM.