Dell M50 / NVidia Quadro4 700 / Windows XP

I have a Dell Precision M50 notebook with the following specs:

Windows 2000 SP4
P4-M 2.4GHz w/ 1 GB RAM
NVidia Quadro4 700 GoGL video, driver revision 6.13.10.4202 A01

I frequently use the notebook in docked mode, with an external flat
panel LCD monitor. The NVidia chipset allows the external monitor and
the notebook display to act as a dual display system, where I use the
flat panel as my primary display, and span the desktop across the
secondary notebook display.

The options to activate the dual display under the NVidia control
panel are listed as 'Standard (NView disabled), 'Clone', 'Horizontal
Span', and 'Vertical Span', where I choose 'Horizontal Span' to
display across both monitors.

I recently did a clean install of the OS on a different hard drive,
but with Windows XP instead of Windows 2000. I downloaded the NVidia
driver for the machine off of Dell's site, and it has a revision of
6.13.10.4257 A02.

The NVidia control panel only has options for 'Standard' or 'Clone',
but NOT 'Vertical' and 'Horizontal', and thus, I can't seem to get the
displays to span across both monitors in Windows XP like I could in
Windows 2000.

Has anyone been able to get their Precision M50 (or similar machine
with same video chipset) running Windows XP to span the desktops
horizontally? Might this be a limitation of Windows XP, or perhaps
the newer driver revision? The NVidia drivers say that they work for
both Windows 2000 and XP.

tks - please reply to the group and via email.

- brian