Broadcom is a company well-known for their lack of cooperation with open-source developers, even when they have complete code for linux driver!
That also means that one of the more popular 802.11b/g cards, Broadcom 43xx series, is a PITA under linux.
Some time ago I got it working using ndiswrapper 1.38 and XP64 drivers from some other laptop. Sometime later, I upgraded both kernel (126.96.36.199-ck1) and ndiswrapper (1.47) and when I got myself in need to use WiFi, I found it doesn’t work. After long story of shotgun debugging, I finally found a way to make it work.
Install ndiswrapper 1.47 from here.
Download driver sp33008, like:
And use cabextract to extract drivers from exe file:
Now, install driver using ndiswrapper and reload ndiswrapper (Remember to uninstall old one!):
ndiswrapper -i bcmwl5.inf && modprobe -r ndiswrapper && modprobe ndiswrapper
It seems to help with some errors concerning encryption. Your mileage may vary, but there are few variants of this conf file – one of them might work for you, and they are all included with the driver
If all is well, you should have a new network device by the name of wlanx or ethx, depending on your settings, and iwconfig should be able to set up your card.