dl the drivers here
. and move them to /redeemed/home assuming you use redeemed on it.
This is what I do, it saves me grief. Others may differ.
sudo apt-get update
sudo apt-get dist-upgrade
sudo /etc/init.d/kdm stop <-this will shut down X, bring you to a command line.
Do ls. This lists everything in the directory you are in. In this case, your home dir. This way you'll have the name of the file in front of you.
sudo sh NVIDIA-Linux-x86-1.0-9755-pkg1.run <just verify the file name.
accept all the prompts, don't worry if it tells you it has to guess a path or anything.
The only problem you might have is if kubuntu doesn't install a particular file by default that the drivers need. header files and gcc come to mind.
If the install fails for a file do
apt cache search [file_name_here]
then sudo apt-get install [file_name_here]
back to the "sh NVIDIA" part to install drivers
sudo nano /etc/X11/xorg.conf
Look for the resolution lines that are under the "driver" section, where it will say "nvidia" for the driver. ctrl+v is pg down, ctrl+y pg up
Using the same format thats in there
Doing from memory so forgive mistakes please
"1920x1200" "1680x1050" and so on add your native, or desired res in there.
For example, if you want 1600x1200 it would look simply like this.
Then ctrl+o to save, hit enter, then ctrl+x to exit nano
reboot if you like, or do "sudo /etc/init.d/kdm start
For the easy way, look around for your nvidia settings in the menu.
I don't know where it defaults to in KDE, but your display can be changed there also.