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