I don't use networkmanager, but given the error, I would think if you killed the graphical nm-applet, it might work.
You can also replace networkmanager with
wicd, which has a curses interface.
If you list what exactly you're doing with iwconfig, dhclient, etc, we may be able to direct you there. If you're using WPA encryption, you need to use
wpa_supplicant for these to work. If it's just the default gateway you need to add you can do
Code:
route add default gw <gateway address>
The dns server should be taken care of if you're using dhcp. If you need to specify a different dns server, you'll want to edit
/etc/resolv.conf resolve.conf will be overwritten when using dhcp, so you'll need to take
extra steps to avoid that.