I downloaded the virtual machine and installed it on my laptop. I am using vmware player, Turion 64 TL-60, 2 GB RAM. I don`t know why but backtrack 4 final is running extremely slow (the mouse barely move on the screen, if you open a terminal it takes 20 sec to really open...) .
I tried to use the ISO, started it as a live cd, but it is still slow.
Contrary, Backtrack 3 is running very well.
So, I supose that the final version needs a better CPU, or it is an incompatibility with the video card.
I had exact same situation. I took VMware and stripped out everything except CD drive (for image file), CPU, monitor, and RAM then it started working fine...
I slowly added stuff in and came to the conclusion that it was the audio which was causing my system to consume all the resources and cause BT4 to slow WAY down.
If you start BT4 and have no audio, that may be the reason and a simple uninstall/disconnect of the audio in VMWare will solve this problem.
P.S. I have SigmaTel audio