I've just tried it for you, Scorpion - works fine for me
Looks like it's due to something at your end...
What exactly have you changed?
What's your set-up now, & what was it before?
What are your network settings?
EDIT: Ah...although I just tried again & it didn't work. Tried a 3rd time & it did. Maybe it isn't you afterall, & there's a problem at the moment...
EDIT again:
www.xbox.com says that "XBox Live is Up & Running"