Hi, I think the page you linked to is based on an early version of my howto on the ubuntu forums
Unfortunately there seems to be a few mistakes in that page and a few very important steps are missing
Just follow all
the steps in my howto (you've already done "step 1" and "step 3"). Under "step 4" you should follow "part II" (copy / paste the changes in nvmain.c to avoid mistakes).
Hope you get it working. And if you are a registered user on wiki.ubuntuusers.de could you update the instructions?