we have tried entering our dns settings both manually and automatically. both ways the wireless network shows connected, the ip address and dns both show confirmed when you text xbox live connection. but still the mtu test fails. one of the posts says to set NAT to Open, but we never get to the NAT test.

any other thoughts?

OK, so I am the novice mom trying to help my son.... he had his 360 live working when we had verizon dsl. We changed to Verizon FiOs and now he can not connect to 360 Live! Should I interpret your reply to understand that he should not be playing 360Live via Verizon FiOs wirelessly? It worked wirelessly when we had Verizon DSL. The only difference is 1) FiOs vs DSL and 2) the router.... FiOs uses an Actiontec router and DSL used Linksys. The 'MTU' test keeps failing. We have been trying to get this to work for two months, so you can imagine my son is not a happy camper.

Thanks!

I am having the same problem. We have called Microsoft and Verizon and when we test the connection it fails on the MTU test. We have updated the firmware, but still no one can help. Any suggestions? Did u get urs to work?