The proprietary drivers from Nvidia (and anyone for that matter) taint the GPL'ed kernel. That is normal and is not an error. It's just telling you that you are running non-GPL'ed software.
Extract/make install should have worked ok.
Do a /sbin/lsmod | grep nvidia to make sure the module is loaded - should return a line something like nvidia 1698924 10 . Check your /etc/modules.conf file to verify you have the following alias char-major-195 nvidia line in the file. Then check that devices are made by ls /dev/nvidia* . If all of that is in order, and you have made the XF86Config changes, it should rock-n-roll.