Do NOT use firmware (at least from cafeugo) or modules for Broadcom wirless cards - you will experience much pain.

Read this ... please: http://www.linuxquestions.org/questions/showthread.php?t=463002

In short:

1. Blacklist el' bcm43xx
   
2. Install windows driver from here using ndiswrapper
   
3. And the ndiswrapper module as an alias for your ethernet device (ex. eth1).
   

My setup:

djfroofy@kieru:~# uname -a
Linux kieru 2.6.20-15-generic #2 SMP Sat Apr 14 00:54:01 UTC 2007 i686 GNU/Linux

djfroofy@kieru:~# lspci
...
09:00.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5752 Gigabit Ethernet PCI Express (rev 02)
0c:00.0 Network controller: Broadcom Corporation Dell Wireless 1390 WLAN Mini-PCI Card (rev 01)

Finally got wpa encryption working on my laptop ... after lots of pain. It all boiled down to using generic driver (wext) instead of specific ipw2100/2200 (ipw) which was giving me nasty ioctl errors. Here's my kernel details:

$ uname -a
Linux techwood 2.6.14-kanotix-9 #1 PREEMPT Wed Dec 28 10:17:53 CET 2005 i686 GNU/Linux

First you need to verify the settings on your router (WPA Personal, TKIP encryption algorithm, your passphrase). To generate the passphrase key and append to /etc/wpa_supplicant.conf:

$ wpa_passphrase yourssid yourpassphrase >> /etc/wpa_supplicant.conf

I edited my configuration and arrived at the following:

ap_scan=1
fast_reauth=1
network={
    ssid="myessid"
    pairwise=TKIP
    key_mgmt=WPA-PSK
    psk=deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef
    group=TKIP
}

To bring up the interface using wpa_supplicant:

$ wpa_supplicant -B -c /etc/wpa_supplicant.conf -i eth1 -D wext
$ dhclient eth1

I've also found some issues with eth1 getting recognized with ipw2100 driver and kanotix kernel. My hack solution has been to unload and reload ethernet driver and ipw2100 driver in that order, so I've bundled this all into one script:

#!/bin/sh

killall -9 wpa_supplicant &>/dev/null
ifconfig eth1 down &>/dev/null
# cleanly remove and reinsert mods (my ipw2100 hack)
rmmod tg3
rmmod ipw2100
modprobe tg3
modprobe ipw2100
echo "Starting wpasupplicant ..."
wpa_supplicant -B -c /etc/wpa_supplicant.conf -i eth1 -D wext
sleep 2
dhclient eth1

I'm curious if anyone else has had to jump through similar hoops. Anyhow, I'm happy now.