I have such problems (ibook G4), too. Sometimes this procedure helps:
killall dhclient rmmod -v bcm43xx modprobe -v bcm43xx ifconfig eth1 up iwconfig eth1 essid $YOUR_ESSID ifconfig eth1 up dhclient eth1 check, if you have an valid accesspoint (MAC is not 00:00:00....) with iwconfig before you try dhclient -- BCM4306 do not work on powerbook https://launchpad.net/bugs/76685 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
