Its Strange Problem, this problem only ever happens on the Mac Systems in the house, Current Systems: Win7 PC, Imac, Macbook, Ipod,Linux Server Both issues can be fixed with a Reboot to the Mac or the Router & happens both on Wifi & Ethernet. Example scenarios: Dad could be surfing the internet on my Macbook sometimes if i turn my Win7 PC on it kicks him off, and gains the same IP 192.168.0.3. Other: Internet works fine at 2am go to bed turn on the Imac the next day & i get a self assigned IP Address, this also happens on my ipod. I Don't think its the router as i've seen it a few routers that i had. Personally i think its a OSX Bug. where it doesn't release its IP address & renew it correctly. What do you think?