If you happen to still be using WEP for your network, you might want to give the following a try to see just how weak your security really is.
Add the backtrack repos...
sudo sh -c 'echo "deb http://32.repository.backtrack-linux.org revolution main microverse non-free testing" >> /etc/apt/sources.list'
sudo sh -c 'echo "deb http://all.repository.backtrack-linux.org revolution main microverse non-free testing" >> /etc/apt/sources.list'
sudo sh -c 'echo "deb http://all.repository.backtrack-linux.org revolution main microverse non-free testing" >> /etc/apt/sources.list'
sudo apt-get update
sudo apt-get install gerix-wifi-cracker-ng
Run it with
gksudo python /usr/share/gerix-wifi-cracker-ng/gerix.py
