Re: Nvidia Drivers
Your log file reveals that you are compiling against the wrong module version.
2.6.12-mdk and then a different 2.6.13-mdk.
I didn't pinpoint it exactly. But either you're running a 2.6.12 kernel with 2.6.13-mdk headers and sources. Or you are running a 2.6.13 kernel with 2.6.12 headers and source code.
You should compile and run your own custom kernel. Or if you're not comfortable doing that, make sure that you are running the kernel that matches your sources.
According to your log your headers are found in the /usr/src/linux directory.
If you're running Ubuntu (which is really just debian set up in a more user friendly way than normal) you can probably run the dselect program at a terminal to see which headers you have installed.
Type in the '/' character and enter <linux-headers> as a search to find which headers you have installed or to install the ones you wish to use.