I have been using Mac systems for a long time now but have not faced such problems in it. I have recently bought a Macbook which had Mac OS X 10.5 on it. I used to connect the Macbook to Internet using Wireless connection to the Linksys router. I upgraded the operating system on the Macbook to Mac OS X 10.6.2 but after upgradation the Macbook is not able to connect to Internet through Wireless router. Whenever I turn on the Wifi the system shows Self assigned IP address. I dont know what does Self assigned IP address in Macbook means and hence need your help. Is this some kind of hardware failure or Is this some kind of software failure? Please help.