My June 09 MacBook Pro has massive problems staying connected to my Airport Express or Airport Extreme - it'll intermittently disconnect, not be able to connect and the range is dreadful. My partner's Macbook and our iPhones have no problems at all. My MBP had a new Airport card, screen and HDD(?!) installed by Apple, but it still won't connect to our network (called 'Free Public WiFi'). However, and here's the really odd bit, I used my old Linksys WRT54G wifi router for over a month and there wasn't a single problem - revert back to my week-old Extreme or my 18 month old Express and the problems return. What could it be?!