all right i watched your video, the first solution that comes to my mind is to go live at your friends house, but that is not the anwer you are hoping for.
does your friend have the same settings? so same ftp program and firewall settings and same windows os?
but some of my other thoughts:
i assume you have tried another ftp program to access your xbox?
have you tried giving it a fixed ip address (keep in mind that the pass and login is xbox!!)? be sure that the ip address that you give it is in the domain of your router!
is your xbox recognized within your network if you run xbmc? i assume you also have installed xbmc (like everyone else) and if you make one (any) share on your own computer, you should be able to access that share on your xbox using xbmc. that is one easy way to verify that your xbox is connected to your network, no ftp program needed to test this.
check your firewall settings on your computer and router (i personally disable them all within in my private network)
if you have a cross cable, try to connect using that cross cable directly. so pc to xbox, no using your router . if that works, there i a security setting in your router that prohibits connection.
