Little Help Please..

Ok so im sick of people using standby against me so i decided to start bridging and giving one of my friends host to ensure of our fair game.

My set up is easy...2 cards in back of comp..one goes to the wall, the other is a crossover to my xbox..easy enough?

I bridge the too...downloaded cain and able, and zonealarm Pro..

i have my new net work set as "internet"
bungie = 65.59.234.161....trusted
Xbox live = 207.246.46.6.....trusted
friends ip= bla.bla.bla.bla...........trusted

I then set my firewall to high and trusted to medium..

he creates a new party and i join..he starts the game..

HE HAS HOST!!!!

NOT!!

We get host boxes, and they get filled with players..
once we get to step three, it keeps us in step 3 for about4-5 seconds and kicks us back to step one..

please help..

P.S. i know there are alot of threads on bridging, but i couldnt find any with this same problem as me..and please dont ban me for asking this..i dont use it to cheat..if i did, i would ask another bridger what i am doing wrong..but i dont know any..i just dont wanna get cheated anymore..please help me!!