External monitor

I'm running Vista Business on a Dell Inspiron laptop. Actually I have 3
identical machines. Each has a second external monitor on the left (because
of the furniture configuration). We also have several older Dell Inspiron
laptops running XP SP2 with a second external monitor on the left. The XP
machines all work fine; but all of the Vista machines do not.

Each of the Vista machines was purchased after Feb 1, 2007, and were
configured with Vista at the time of purchase by Dell.

We reported the problem to Dell, but Dell says it is a Vista problem and is
therefore a "non-issue" for them, because they say it will be fixed in SP1.

The Vista machines use NVidia GeForce Go 7900 GS display adapters, with 256
MB of video RAM. We have the latest version of the NVidia drivers and the
latest version of the BIOS.

Here is the issue: when I restart the computer (after shutdown or sleep),
and get the desktop, the monitor is on the left (moving the mouse) for about
2 seconds. The screen goes black for a couple seconds and reappears again,
but now on the right. I have to change the Display Settings under
Personalization and put the external monitor back on the left.

Is there a way to keep the monitor on the left like in XP?

Thanks,
Bob Campbell