Thanks first to: Link at http://www.ubuntugeek.com/
Make sure you are using the latest wifi drivers:
http://snapshots.madwifi.org/special/
If so, you just need to get to the directory you have the madwifi-nr-r3366+ar5007 (or similar) file in:
e.g. cd ~/Desktop/storage/madwifi-nr-r3366+ar5007 in my case
Then:
sudo make
sudo make install
sudo modprobe ath_pci
sudo reboot
If not, you must do the following first:
wget http://snapshots.madwifi.org/special/madwifi-nr-r3366+ar5007.tar.gz
tar xfz madwifi-nr-r3366+ar5007.tar.gz