Hello Xianoa,
Sorry for the delay in response.
I can't say I'm an Xbox Live expert, but I believe Xbox Live won't work with every router. I do know I had problems myself with WPA security set up. It would only work with WEP. So if you have WPA, that may be causing the problem.
When you perform an internet connection test on Xbox Live, where does it fail? You can search their support site for ideas on what could be causing the problem according to where the test stops.
Hope that helps!
