WPA + DWL-G520 + madwifi

[Fabien R <the_edge456.nospam@club-internet.fr>]

Bonjour,

J'essaie de configurer ma carte dlink pilotée par madwifi à l'aide de 
wpa_supplicant mais l'erreur suivante se produit:

Trying to associate with <modem-mac> (SSID='xxxx-xxxxx' freq=2417 MHz)
ioctl[IEEE80211_IOCTL_SETMLME]: Argument list too long
Association request to the driver failed
Associated with <modem-mac>
WPA: Key negotiation completed with <modem-mac> [PTK=CCMP GTK=TKIP]
Disconnect event - remove keys

Voici le contenu de mon fichier interfaces
# The DWL-G520 network interface
auto ath0
iface ath0 inet dhcp
pre-up /usr/sbin/wpa_supplicant -w -Dmadwifi -iath0 -c/etc/wpa_supplicant.conf
#post-down killall -q wpa_supplicant

Voici le résultat de la commande iwlist
iwlist ath0 scan
ath0      Scan completed :
          Cell 01 - Address: <modem-mac>
                    ESSID:"xxxx-xxxxx"
                    Mode:Master
                    Frequency:2.417 GHz (Channel 2)
                    Quality=26/94  Signal level=-69 dBm  Noise level=-95 dBm
                    Encryption key:on
                    Bit Rate:1 Mb/s
                    Bit Rate:2 Mb/s
                    Bit Rate:5 Mb/s
                    Bit Rate:6 Mb/s
                    Bit Rate:9 Mb/s
                    Bit Rate:11 Mb/s
                    Bit Rate:12 Mb/s
                    Bit Rate:18 Mb/s
                    Bit Rate:24 Mb/s
                    Bit Rate:36 Mb/s
                    Bit Rate:48 Mb/s
                    Bit Rate:54 Mb/s

Mon modem est configuré en AP sur le canal 2 et l'authentification se fait en 
WPA-PSK AES ou TKIP.

Quel peut-être le pb ?

D'avance merci,
Fabien