I would rebuild the module, as anytime xorg or the kernel get an update, I have had to rebuild my modules.
Module assistant is quick and easy to use and will build the module for all your installed kernels I believe.
Code:
sudo aptitude install module-assistant
sudo m-a update
sudo m-a a-i nvidia
m-a is a symlink to module-assistant so you don't have to type the long words. the update line works like aptitude update and searches for available module source code in the repositories. the third line will a-i (autobuild and install) the module you specify. You can also just run
sudo m-a and you get an ncurses frontend to module-assistant.
http://ubuntuforums.org/archive/index.php/t-39879.html
Or you can keep using the nvidia installer, which I think you have to if you want to use the new beta drivers from nvidia instead of the "stable" drivers.