在我的机器上，如果执行modprobe iwl3945，会存在如下错误：
FATAL: Error inserting iwl3945 (/lib/modules/2.6.22-14-generic/Ubuntu/wireless/iwlwifi/iwlwifi/origin/iwl3945.ko): Unknown symbol in module, or unknown parameter (see dmesg)
dmesg:
[ 112.528000] iwl3945: Unknown symbol iwlwifi_ieee80211_rx_irqsafe
[ 112.528000] iwl3945: Unknown symbol iwlwifi_ieee80211_get_hdrlen
[ 112.528000] iwl3945: Unknown symbol iwlwifi_iwlwifi_ieee80211_tx_status_irqsafe
[ 112.528000] iwl3945: Unknown symbol iwlwifi_iwlwifi_ieee80211_stop_queues
[ 112.528000] iwl3945: Unknown symbol iwlwifi_ieee80211_tx_status
[ 112.528000] iwl3945: Unknown symbol iwlwifi_ieee80211_rate_control_unregister
[ 112.528000] iwl3945: Unknown symbol iwlwifi_ieee80211_stop_queue
[ 112.528000] iwl3945: Unknown symbol iwlwifi_sta_info_put
[ 112.528000] iwl3945: Unknown symbol iwlwifi_ieee80211_free_hw
[ 112.528000] iwl3945: Unknown symbol iwlwifi_ieee80211_beacon_get
[ 112.528000] iwl3945: Unknown symbol iwlwifi_sta_info_get
[ 112.528000] iwl3945: Unknown symbol iwlwifi_ieee80211_alloc_hw
[ 112.528000] iwl3945: Unknown symbol iwlwifi_ieee80211_scan_completed
[ 112.528000] iwl3945: Unknown symbol iwlwifi_ieee80211_register_hw
[ 112.528000] iwl3945: Unknown symbol iwlwifi_ieee80211_wake_queue
[ 112.528000] iwl3945: Unknown symbol iwlwifi_ieee80211_rate_control_register
[ 112.528000] iwl3945: Unknown symbol iwlwifi_iwlwifi_ieee80211_register_hwmode
[ 112.532000] iwl3945: Unknown symbol iwlwifi_ieee80211_unregister_hw
[ 112.532000] iwl3945: Unknown symbol iwlwifi_ieee80211_start_queues
如果把第一种方式编译的驱动卸载掉，并加载第二种方式的驱动，就解决了问题：
sudo modprobe -r ipw3945
sudo modprobe -r ieee80211
sudo modprobe -r ieee80211_crypt
sudo modprobe -r mac80211
sudo modprobe iwlwifi_mac80211
sudo modprobe iwl3945
成功。好了，试试看：
% ifconfig wlan0_rename up
% iwconfig wlan0_rename
可以看到：
wlan0_rename: unassociated ESSID:off/any
Mode:Managed Channel=0 Access Point: 00:00:00:00:00:00
Bit Rate=0 kb/s Tx-Power=20 dBm
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
okey，驱动已经没问题了，按平常操作的方式配置无线网络即可。