I try to boot the new Backtrack Beta 3 on my laptop and it doesn't work for me

My laptop have a Dual Core cpu and the Ati X1450 graphic card.

I select the Boot with kde in the boot menu and then i add the username and password as normal and then i use the command startx and i get this :

Fatal server error:
no screens found
giving up.
xinit: Connection reset by peer (errno 104): unable to connect to X server
xinit: No such process (errno 3): Server error.

Is this a problem with the Backtrack 3 Live cd or i do something wrong?

Backtrack 2 it was ok!

Thanks all of you!