prob connecting xbox live

[pappyduff]

Hi everyone,
firstly please be patient with me as I am very new to gaming consoles. the problem is I have been using my sons xbox to play online (live) and all was fine until aou aweek ago when it would only allow me live for about 2 mins. i am connecting wirelessly via a bt homehub and had no problems till as i say about a week ago. My pc is working ok and i use the same router home hub via a belkin usb wireless link. does anyone understand what is happening and can they possibly help me or do I have to be disowned by my Son.
Thanks in anticipation.
Pappyduff