nono.... forget the wpa_supplicant.ath0 in /var/run
this is created in runtime.
do... #> ifdown ath0
go to /etc/wpa_supplicant and edit wpa_supplicant.conf
do something like this
when done, (ath0 is still down) do
proto=RSN #this is for WPA2, use proto=WPA for wpa personal
pairwise=CCMP TKIP #this is for WPA2, use or CCMP (aes) or TKIP
#> wpa_supplicant -Dmadwifi -iath0 -c/etc/wpa_supplicant/wpa_supplicant.conf
that would do...