I installed Ubuntu Feisty Fawn on my Compaq NC6000 which has an Intel PRO 2200BG wireless card. Could not connect at all to my home network (WPA-PSK encrypted network running off a Netgear Access Point). The laptop could not even see any networks even after I enabled the SSID to be broadcast from the router.
The following fix got it to work:
sudo apt-get install wpasupplicant (Feisty Fawn already has this installed though)
sudo apt-get install network-manager-gnome network-manager
sudo gedit /etc/network/interfaces (Comment out everything other than “lo” entries in that file and save the file)
Create a file called /etc/default/wpasupplicant, add entry ENABLED=0 and save the file
sudo touch /etc/default/wpasupplicant
Reboot your system or use the following command
sudo /etc/init.d/dbus restart
Left-clicking the network manager on the top of the screen then showed all networks in the vicinity. I was then able to select my network, configure and enter the password. Once this was done I could re-hide the SSID on my router.