the Hushed Casket

Hi I got a doosy for you. I currently runnig DSl with a Motorola 2Wire modem with a built in 4 port router. I then have 1 wire run to my room to a Netgear WGR614v4 router, then I have my computer and Xbox 360 off the router. Now in the living room my roommate has 1 wire off the modem into a Linksys WRT54G. She then has her computer and Xbox 360 off her router. In case your wondering the other two ports on the modem are used by two other individuals with pcs elsewhere in the house. Now the problem you described is the same problem we are having, we cannot hear each other or join each others room. If a person outside our network hosts the room we can join and play no problem. The problem only occurs when either of us try to host the room. Now if we bypass the routers and go straight of the modem, there is no problems. So we know it's the routers that are conflicting. Also if one of us is hooked straight to the modem and another is on the router, we can join the room together but the communicators are all weird she can hear me, but I can't hear or vice versa. This is only with the Xboxes, we can all in the house on our PCs at the same time no problem, it is only when me and roomate try and play Halo 2. If we both play a different game ie: me on battlefield, her on Halo, we are fine. There has even been times we have both played Halo in seperate rooms just fine. It only effects when we try to join up and communicate over the headsets. Also both of our Xboxs NAT are set to Open, and we have opened our ports on our routers using the 88 UDP, 3074 UDP and the 3074 TCP, well she did that, I am only allowed on my router to open 88 UDP and 3074 TCP, when I try and open the 3074 UDP my router say conflicting port. Please help us.