Comment 3 for bug 216658

Also you can build latest madwifi (0.9.4). Short HowTo:

1- Install build stuff:

sudo apt-get install build-essential

2- Download madwifi from http://downloads.sourceforge.net/madwifi/madwifi-0.9.4.tar.gz

3- Unpack, remove ubuntu madwifi modules, build, install, load module

tar xvzf madwifi-0.9.4.tar.gz
cd madwifi-0.9.4
sudo ./scripts/find-madwifi-modules.sh `uname -r`

[Select remove option]

make
sudo make install
sudo modprobe ath_pci

4- Right click on NetworkManager, disable it, enable it again ... and you're done!