How do I span the desktop on nVidia 5600?

Hi, I have the GeForce4 FX 5600 on a Sony Vaio. I don't see an option for
monitor spanning in the display properties - only Clone or Standard (Dual
View). If I click Clone I can get a replica image on my TV, but if I click
Standard, I get nothing on the TV.

The TV is connected to the nVidia out via S-Video and is on.

Want I want is to span the desktop so the left half is on my Flatscreen and
the right on my TV (for watching Media Center Edition content).

There seems to be no option in nView. Also, I used to see 2 monitors in the
standard Windows Display Settings tab on my old PC with a GeForce 4 FX 440,
but now I see only 1 monitor on the 5600.

Any ideas?

Thanks in advance.
J.