Resolution Changes when Switching Users

I recently created a separate user account for my wife on my Vista Home
Premium computer. When I switch between users, the resolution continually
changes back to some kind of default (1280x1024) rather than the preferred
resolution for the monitor (1920x1200). I also have a projector attached to
the system, which is at 1280x1024 regardless of switching users or not.
Also, the screen where I'm allowed to chose which user to log on as is at
1280x1024. I think if I can change that user selection screen, I can get my
two user accounts to work correctly, but I'm not positive about that. Does
anyone have any thoughts?