Thanks for posting this - I just installed Linux Debian - Kernel 3.0 - I missed this thread, good on me - so took a few hours of pulling it all together but managed to set up nvidia and compiz.
I mainly post this here for those who are interested in a slightly alternative way, as the way I read it there is a bug in
http://bugs.debian.org/504692 nvidia-config and most of the approaches I found didn't combine both nvidia and compiz instructions, or work fully for me.
Cheers
C.
#note: this is not a script just a collection of instructions
#determine your kernel version
uname -r
#confirm that you have the kernel headers installed
#linux-headers-<version>
apt search linux-headers-
#run script to determine if the correct nvidia driver is available on your system
#http://wiki.debian.org/NvidiaGraphicsDrivers?action=AttachFile&do=view&target=nvidia-versions.sh
#the script can be updated with new infromation, theinstructions are at the bottom of the script
#bash nvidia-versions.sh
#remove nouveau as it conflicts with nvidia
sudo apt remove xserver-xorg-video-nouveau
#install and compile the nvidia kernal drivers
sudo apt install nvidia-kernel-dkms
#confirm the install of glx worked
apt-get install nvidia-glx${VERSION}
#backup your xorg.conf file
#although you may not have one if it is a new install
cp -p /etc/X11/xorg.conf /etc/X11/xorg.conf.bak
#note there is a known bug in the app nvidia-xconfig
#http://bugs.debian.org/504692
#alter or create a new xorg.config
gksudo gedit /etc/X11/xorg.conf
#add the following content
#Section "Module"
# Load "glx"
#EndSection
#Section "Device"
# Identifier "Video Card"
# Driver "nvidia"
# Option "AddARGBVisuals" "True"
# Option "AddARGBGLXVisuals" "True"
#EndSection
#save and close everything
#restart x - use keyboard or reboot as there is a bug in gdm3
#http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=590534
#ctrl-alt-bkspc
#confirm that it is now working
glxinfo |grep rendering
#direct rendering: yes -- is good
#create file
gksudo gedit ~/.gnomerc
#add the following line without the #s
#export WINDOW_MANAGER=/usr/bin/compiz
#save the file and reboot