John R. Lewis, MCP

I just installed Vista Business on my Dell XPS M170 laptop. I had been
running Vista RC1 with few problems.
I have an external 19" flat panel monitor connected to the DVI port on the
laptop, and have configured it as second monitor. I have it set up so that it
is to the left of my laptop screen (the laptop is the "primary" monitor).
This works fine until I lock the laptop.
I find that under the RTM version, when I unlock the laptop, the screens
appear normal for a second or two, then the orientaion "flips", i.e. the
external monitor now appears on the right side of the laptop screen. I can go
back and change it, but this happens *every* time I lock the laptop. Does
this seem to be a driver specfic issue? I am using the driver that Vista
installed automatically (NVIDIA GeForce Go 7800 GTX, V7.15.10.9746). I never
had this problem using RC1.