Nvidia propietary driver

[TRINGALINVENT at libero.it]

Hello everybody,
a friend of mine has a notebook with Kubuntu 9.10, and has many problems with the video driver: the computer is an ASUS M50Vn with a graphic card NVIDIA  geforce 9650m GT. Searching on internet we found out that it is a known bug, but the only solution is to use old drivers version 173. Anyway, with those drivers graphics is VERY SLOW, quite unuseful.  Someone in a forum post said that there were no problems with Kubuntu 9.04. 
So I'm asking... does anyone know how to make propietary drivers work good? Will Lucid Linx have a solution for this problem?