no screen found nvidia GF 540m with Optimus Technology

i can use BT3 and its working but when i boot backtrack i get message no scree found and fatal server error message .i have navidia FG540m 2GB dual gpu with hd resoultion 1366+768 .
but when i use gnack track same like backtrack .its new ver 6 working great with no problem . please this is main error

xinit: connection refused (errno 111): unable to connect to x server
xnit: No such process (errno 3): server error

Upgrade to the latest Backtrack 4 R2 and also install the nvidia drivers.
Backtrack 3 is no longer supported.