Do you see the NVIDIA eye logo pop up while the system trys to start X?
I have been working on this same problem for tow weeks now, and last night had some breakthroughs!
I I found the NVdriver file existed nowhere on my system.
So I downloaded the source tarball, compiled it, and checked for all the files. All the files were now in place, but still no work.
Doing some more reasearch, I found that the instructions left out one step, "modprobe NVdriver".
Once I ran that, everthing came up with openGL working!
By the way, as a learning experience, I refused to reinstall. I learned quite a bit about Linux with this and some other problems that crept into the system as updates and new software were installed.
Most of the help came from user groups like this one.