If you have this graphics and want to get compiz to work in Backtrack 4...

First of all you need to download the driver witch is here at this link. Then it can't be any simpler than this make sure you remember where you download it at OK..

Now open up a terminal and go into the directory where its saved and just run this exact command and a friendly interactice installer will come up just make sure it stays on automatic

root@YOU:~# cd Driver/
root@YOU:~/Driver# ls
root@YOU:~/Driver# sh ./ati-driver-installer-9-10-x86.x86_64.run
Make sure your doing all this as root.

P.S This will work for all ATI Radeon 3xxx only, so that would be any of the 3000 series..

If this helped i wouldn't mind some comments ^_^