None of the solution so far have worked. I just can't get 8178 to boot. There's gotta be something in the kernel modules that's still 7667 but i've got no clue as to what.
To highlight my exact situation:
OS: Ubuntu Breezy Badger 5.10
Kernel: 2.6.12-10-386(image downloaded from the repositories, precompiled)
Nvidia driver 7667 works well everytime. 8178 works after beeing installed but after a reboot, when X starts it fails to start and displays the exact same error:
ERR: API mismatch: NVIDIA kernel module is version 1.0.7667 but this X module is version 1.0.8178.
YESS! I got it to work! The solution was to install the kernel image and headers, which i had done, then sudo apt-get --purge remove nvidia-glx linux-restricted-modules-`uname -r`. Then uninstall whatever driver ver. you had whilst receiving an error about a missing symlink and install a new 8178. And it works!