I recently got my brother's xbox and tried to hook it up at my house. It sees my wireless network but cannot connect. I've double checked the password, tried setting an alternate MAC address the same as my computer, and set up a manual IP address, all with no luck. The xbox always connected fine at my brother's house, and we've never had problems with laptops connecting here. Any advice?
Only think i can say is if it connects at your brothers then something in the network settings for your connection have to be wrong. As a test have you tried disabling your security, setting the xbox to DHCP (automatic) and then trying to connect?
And if you are 100% sure all the network setting on the xbox are correct have you tried unplugging your modem and router and cycling your system and then trying to connect with the Xbox?