Here's how you're going to get this working... when i suggest something and you try it, even if it doesn't work, don't go back to the way you had cause its just wrong and we need to make progress.
for example i had posted up top more this:
"change the xbox ip to 192.168.1.3 and the pc crossover nic to 192.168.1.2 subnet 255.255.255.0 for both.
no gateway."
and yet you just posted you are using 192.168.0.4 on your pc and 192.168.0.5 on your xbox
PLEASE MAKE THAT CHANGE. but leave the other nic in your system that is NOT connected to the xbox at 192.168.0.2
Also, do not make the gateway the same as the nic ip address. In fact all your gateway's should say 192.168.0.1, even the ones connected with crossover to xbox, it won't hurt anything.
Once all this is set try it. If it doesn't work don't go back the way it was. just post if you can ping or what exact error you get from the ftp.