held with xbox ftp'ing

[geekwiglasses]

hi all,

recently got a modded xbox(with evo-x)

got a crossover cable, connected pc and xbox through the ethernet ports of both machines, running flash fxp.

i enter the ip of the xbox and the user, password etc

when i click to connect it times out after about 20 seconds

when i turn my cable modem(which is connected via seperate usb port) off and try it, it says "no route to source"

it is really baffling me can someone help?
what do i need to configure with the pc or xbox?

please help

thanks,
rob.