So I have run into the same exact issue! And delved into the world of Networking issues to no avail. Along with the following Things That Did Not Work: -Exiting out game Reset Xbox -Reset router -Reset gateway for router -Reset router to factory settings -Reset to factory defaults on Xbox -Setting Xbox to Static IP address, (thinking this would help). -Enabled Port Forwarding on for ports TCP & USP 53, TCP & UDP 3074, TCP 80, and UDP 88. -Enabled UPnP -DMZ on with port forwarding off -Reset Xbox software by clearing cache and reinstalling update. -Calling Comcast and having them do the same resets and changing router channel. -Port triggering for the ports mentioned above when more than one Xbox is in use, port forwarding off, DMZ off -Wiring the Ethernet cord to each device -Another multiple resets -More resets... I'm also trying to use multiple consoles, we have 2 Xbox360's in our house, however this issue occurs even when only one of us is on. I'm going to try to set up what you said before ultimately getting another router.