I've only been able to make this work using the link provided below by adding the livna repository to yum and update per the instructions listed in the link given. Nothing I tried in this forum worked. As a side note, I also noticed how poorly the Fedora 6 installer upgrades from Fedora 5. I had to update KDE in text mode using yum before I could get to the desktop, after upgrading the nvidia drivers from livna of course. Good luck!
livna Nvidia drivers, install help, etc.