My friend's MacBook (last generation?) will 'connect' to her wireless network, display a quick error (Wireless network does not exist), claim it is still connected, but get no internet. Connected to an ethernet cable coming out of the router it gets internet fine. Other computers in the house (ancient HP PC, 3G iMac) and my iPod Touch connect just fine and get internet. She took it down to the mac geniuses but they were pretty unsure of what exactly to do, since it's not like they were sitting in her living room. I believe the router is a linksys, and her mac is running OS 10.4 I'm sorry the details are sort of vague, but frankly I don't know where to begin with this problem. I've tried resetting the cable modem and the router. Any ideas would be GREATLY APPRECIATED!