I had hair pulling experience installing nvidia drivers on Backtrack-linux, be it the driver from http://www.nvidia.com or nvidia-current from backtrack repository, I got error on DKMS building or got error to build nvidia.ko and X could not start.
I have googled for many solutions for hours:
1. http://samiux.blogspot.com/2011/05/howto-bug-fix-for-backtrack-5.html
This looked promising, but not working for my situation.
This looked promising as well, not working at all, there are errors in the syntax though.
3. http://ewangi.info/660/backtrack-5r1-first-hot-review-bugs-fixes/
After hours of finding with the correct keywords with google, this solution actually worked for my situation!
Blacklist
nano /etc/modprode.d/blacklist.conf
blacklist vga16fb
blacklist nouveau
blacklist nvidiafb
blacklist rivatv
blacklist rivafb
This blacklist configuration file is to prevent loading of the drivers especially nouveau, nouveau conflicts with nvidia.
Remove nvidia completely
apt-get remove –purge nvidia-*
This is to start clean. Then reboot.
Add ubuntu repository
add-apt-repository ppa:ubuntu-x-swat/x-updates
To use add-apt-repository you need to install python-software-properties
Install nvidia-current
apt-get update
apt-get install nvidia-current nvidia-current-modaliases nvidia-settings
When you choose to install nvidia-current, nvidia-settings will be installed as well.
Reboot. No need to run nvidia-xconfig.
Backtrack-linux nvidia-current is 195.36.24 whereas the ubuntu’s nvidia-current is 290.10 which is the latest. I wanted to use the CUDA feature which made me motivated to install nvidia-current driver…
cyruslab 
Really enjoyed reading some of the posts on this site. Have linked it to E-WOT so I can come back!
how to install cuda .
root@bt:~# apt-get install cuda-sdk cuda-toolkit
Reading package lists… Done
Building dependency tree
Reading state information… Done
E: Couldn’t find package cuda-sdk
thanks,in advance
ivar, it means your repository servers do not contain cuda sdk and toolkit, instead use this instruction for backtrack 5 http://www.backtrack-linux.org/wiki/index.php/CUDA_On_BackTrack, you have to install cuda by downloading the script file from nvidia.
thanks for the reply
i had an another problem
screen resolution is not changing, i edited /usr/share/xresprobe/xorg.conf and i changed values from 1024×768 to 1440×900 and it is not working .
please help me.
Ivar, try to change from /etc/default/grub. Look for GRUB_GFXMODE and change your resolution there, save the grub then do update-grub.
thanks for the reply
completed my cuda work
i changed GRUB_GFXMODE=1024×768 to GRUB_GFXMODE=1440×900
reboot
but not going into 1440×900
is there any other way
if you install the nvidia driver, then you should use the nvidia settings to adjust the resolution, you should not modify the xorg.conf file.