you are posting your request in the wrong place,
anyways
it seems that there is a misconfiguration in your X server
when you boot up with back track, instead of typing startx to use the graphical mode
try to find your graphic card by typing this command
this should return a rsult like this :
Code:
01:00.0 VGA compatible controller: nVidia Corporation GeForce 8800 GT (rev a2)
and it depends on your graphic card
then try to find a linux driver for your graphic card and install it, then try to configure your /etc/X11/xorg.conf file