What if you're using Debian instead of Ubuntu? Using Debian it's much tougher get compiz-fusion running.

Debian does not have an option to use propriatary drivers. You have to do it manually. To be able to install the drivers, you need your kernel headers first.

uname -a

aptitude search linux-header-2.6.24

aptitude install linux-headers-2.6.24-12-generic

where 2.6.24-14-generic was the return value from the uname command. Those values might be different on your machine.

cd /usr/src:
ln -s /usr/src/linux-headers-2.6.24-12-generic linux