Sometimes there are those days... Tonight seems one to !
Removed the Quadro VGS card from the computer, cloned the SSD back to original and booted.
Connected the second screen, expanded the desktop and scrolled to the second screen with the mouse.
What's that gap between the two screens ? Back to settings, there are 3 (three !!) screens ?
Screen 1 and 3 connected to the nVidia 9800, screen 3 on the Intel motherboard ??
Connected a third screen to the internal vga and i have an extra desktop screen !
Unbelivable, tryed en tryed, and then when your not trying anymore it works on itself !
So it look like i don't need a extra video card !