Welcome to SL.
tmacuk wrote:after tampering with ndiswrapper I got that working quite well (although I cannot get it to run on boot up even after adding ndiswrapper to /etc/modules)"
You have to declare modules you want to be loaded at boot in /etc/conf.d/modules, not /etc/modules.
tmacuk wrote:Why won't the WEP security work on my laptop?
No idea. It's not a general problem with SL, as WEP works fine for me, but then I don't use NDISwrapper (some other SL users do, though). Have a look at the SL Wiki article Using Broadcom wireless and ndiswrapper w/Sabayon miniEd
in case that gives you some ideas. I know it's not your hardware, but it shows how to set up WEP with NDISwrapper, so it might point you in the right direction.