User Switching Video Error

Hello,

I just set up an additional user on my Vista Home Premium machine. Upon
startup, I can go into either user, all works fine. But when I log off, or
go to switch user, the video goes blank and an error comes up (monitor
driven error, on screen display for monitor) and it states, Video Sync
Setting Too High. I cannot get anything back working, have to restart again.
Is this a common problem and is there a fix ?

Thanks

Steve