Наверное, eth0 - это всё-таки не Wi-Fi, а встроенная сетевуха.
root@phenix:/home/user# iwconfig
lo no wireless extensions.
eth1 no wireless extensions.
eth0 unassociated ESSID:off/any
Mode:Managed Channel=0 Access Point: Not-Associated
Bit Rate:0 kb/s Tx-Power=20 dBm Sensitivity=8/0
Retry limit:7 RTS thr:off Fragment thr:off
Encryption key:off
Power Management:off
Link Quality:0 Signal level:0 Noise level:0
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0
sit0 no wireless extensions.
Для примера
до включения карты
leo@leo-laptop:~$ iwconfig
lo no wireless extensions.
eth1 no wireless extensions.
eth0 no wireless extensions.
sit0 no wireless extensions.
leo@leo-laptop:~$
и после
leo@leo-laptop:~$ iwconfig
lo no wireless extensions.
eth1 IEEE 802.11g ESSID:"Savoy"
Mode:Managed Frequency:2.412 GHz Access Point: 00:12:17:E7:8F:96
Bit Rate=54 Mb/s Tx-Power=20 dBm Sensitivity=8/0
Retry limit:7 RTS thr:off Fragment thr:off
Power Management:off
Link Quality=55/100 Signal level=-68 dBm Noise level=-82 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:1 Missed beacon:0
eth0 no wireless extensions.
sit0 no wireless extensions.
leo@leo-laptop:~$