i think this can be solved . first you should check router settings and password . if not working please reset the router and if still not working than contact with support at http://belkin.technical-care.com/ i hope this may help you ..thanks
i think it should be port forwording problem or it could be a password authentication problem . i would suggest you to reset the router .and setup the password once again . change the password type . and now try to connect to x box 360 once again .