Whats happening is Airport will disconnect itself from the wireless network, and then it wont detect it again when you scan for wireless networks. So then I have to turn Airport off and on again, and then scan and reconnect. There is something obviously wrong, and any help will be welcome. I have done a permissions repair, gone through the Airport utility, re-set the P-RAM, and gone through the network preferences. Nothing seems to make any difference. The computer is a 17" Al Powerbook G4, 1.67 GHz. Base station is Apple Airport Extreme (Older white round unit, not rectangular). Havent had any problems in the past, only started after I installed a larger hardrive and installed Leopard on it.