my xbox live connection was fine upto 2 weeks ago, now i get kicked from xbox live and am losing skill on halo 3 rapidly

is this a virgin media issue?? i have reset the router, checked the firmware and all other settings, Unpp is on and port forwarding off, i have a netgear wg264T router, live approved, everything else is cool, internet and all, just the xbox, was working perfectly previously to help !!
