For a while, I had my old Linksys router strung through the FiOS router. My 360 was able to pick up my Linksys that way. It was working fine wirelessly until I had a power outage that reset the Linksys router. I couldn't reset the Linksys router because, of course, if I unplug the FiOS router I have no net access. And I couldn't figure out another way to reset it. I was gonna reset it over my boy's place, but I haven't gotten around to it. I just hard-wire the connection for now.

I've read that some folks are able to use the original Xbox wireless router with the 360 and it works fine. Good luck trying to find one though. Not sure it's worth the trouble for a shot in the dark.

That FiOS router is not going to cooperate, though.