connecting xbox

[frequency]

hey guys i never had a problem ftping from my xbox to my pc b4 after i got some help here. but now i have comcast internet. and i also had find out that i had to purchase(which i did) another ip address if i wanted to play xbox live if i wanted to hook up my xbox through a switch(hub). for some reason now i cant seem to connect to my xbox using flashxp. when i run evox it gives me the ip address which i then put that in the flashxp and i hit connect....but it is a no go. i cant seem to connect at all. when i had dsl with a router and hub i never had to purchase another ip address for xbox live to work or to connect my xbox to my pc using a ftp program. so how do i go about fixing my ftp'ing blues.... do i have to put the other ip address that i bought from comcast in the evox ip settings? and if so how do i find that new ip address?