Grant,
I have followe the instructions but still cannot get the essid to set -- all other parameters seem to set OK. I have tried this on two different systems with identical cards and I get the same problem. I am using the bcmwl5a driver -- the driver on the CD and the driver loaded on my XP system (same one) caused my system to lockup.

I downloaded the bcmwl5a driver from a web link which was posted on the this site http://ndiswrapper.sourceforge.net/wiki/index.php/List. Below is the extract from the site which talks about this particulcar card -- I am using the Rev 3 drivers

Which bcmxxxx file are you using ?

Thanks
Steve

Card : Belkin 54g Wireless Desktop Network Card (F5D7000)
Chipset : BCM4306 Board : V1799 D-7000 Rev 4.5
pciid : 14e4:4320
Driver : http://www.belkin.com
Other : This is PCI, not cardbus. The chipset is marked BCM4306, however the supplied utility in win98 detects "BCM4306/BCM2050", and Linux utilities have variously reported; BCM4306, BCM4320, BCM94306. This card has been stable on a Slackware SMP system with ndiswrapper-0.8 since released, versions 0.7 and 0.9 do not work with the SMP kernel.

Card : Belkin 54g Wireless Desktop Network Card (F5D7000) Rev 02
Chipset : BCM94306
Driver : From Installation CD
Other : It is working on Slackware 10 (kernel 2.4.25 and kernel 2.6.8.1)
Also working on Gentoo (using various 2.6.x kernels), however from ndiswrapper > 0.8 the Belkin drivers did not work at all (Oops at modprobe, system lockup); I used the Dell drivers (see the rev 03 entry following this one) instead, and now I'm happily running 0.11.

Card : Belkin 54g Wireless Desktop Network Card (F5D7000) Rev 03
Chipset : BCM4306
pciid : 14e4:4320
Driver : http://ftp.us.dell.com/network/R81433.EXE (use bcmwl5a.inf in directory AR)
Other : I tried to use the belkin driver (bcmwl5.inf) but the whole system just locked up as soon as I modprobed ndiswrapper. Apparently the belkin driver works for the older rev 02 cards, but not rev 03. So I'm suggesting this for folks with the Rev 03 card. You can check the revision by doing a "lspci" The Dell driver has been working great for me, for about a day.
Other : The rev.03 problem is probably not all that sinister. It is caused by the presence of the NetworkType|0 line which ends up in the *.conf files (from the *.inf driver file). Removing this allows the supplied Belkin driver to work, although I'd probably recommend using the Dell R81433.exe driver anyway if only because it's a later version. For non-US users you may wish to edit the Channel parameter to be 13 (Europe) (or 14 in Japan?). Applies to both PCMCIA and PCI versions (F5D7000 and F5D7010).