You can use my PPA at https://edge.launchpad.net/~thefirstm/+archive/ppa
. I always keep the latest nvidia drivers loaded here.
By the way, I was looking at your xorg.conf file and I noticed that it has alot of junk that was put there by the nvidia-xconfig program. Ubuntu 8.10 support HAL-powered Xorg Input Hotplugging, so you shouldn't need the sections for keyboard and mouse. These should be detected automagically.