Run 'netcardconfig' and 'wlcardconfig'(IIRC as root).

I always have to run 'netcardconfig' (refusing DHCP, then accepting all defaults) before I can run 'wlcardconfig'. I then run 'netcardconfig' again, this time saying yes to DHCP so all lan parameters are configured automatically.

HTH

edit - corrected 'wlanconfig' to 'wlcardconfig'