Vista Tutorial - Using Dual Monitors - Won't Retain Settings

Hello. I have a Dell XPS M1710 Laptop that I carry back and forth to
work (where I place it in a docking station). A second monitor is
also attached to the docking station.

In "Display Settings," I have chosen to make the second monitor my
primary monitor, and extend the desktop.

PROBLEM: These settings won't save. Every time the screensaver comes
on, or I restart the computer, the settings revert back and I have to
change them again.

Is this a Vista bug, or something I can fix?

Any help would be appreciated... this is frustrating.

Thanks,
Jessi