CVS is a bit scary at first, but it actually isn't that hard to use. The first thing you
may have to do is start a CVS repository on your machine:
cvs -d /path/to/repositorydirecotry init
Once you've done that (again, I'm not sure you have to), you can access the sourceforge CVS repository anonymously. There is a very good
CVS help section at Sourceforge, but basically you just need to enter:
cvs -d
server:anonymous@cvs.sf.net:/cvsroot/madwifi checkout madwifi
That should download the madwifi project to a madwifi directory below the one you are currently using.
I created a .tar.gz of the current madwif CVS i and emailed you how to reach it if you don't want to try using cvs yourself.