[tlinux-users:08633] cannot activate DVI-port

Hello, 

I have a Satellite P100 with Nvidia go 7900 GTX. This laptop has two video 
output: a VGA and a DVI. 
I used the Windows Vista to verify if the output work well. Everything is 
fine. 
But, using Linux the nvidia-settings cannot recognize the DVI output. 
I want to use two monitor and not the laptop display. The DVI monitor is 
completely ignored by Linux... In TwinView I have the first monitor in the 
laptop display and the second monitor in the VGA monitor. 
I want to disable the laptop display and only use the DVI and the VGA. A 
screeshot of the nidia-settings is attached. 

Thanks for any help. 
Liliane