I just installed the game fresh in a Dell XPS laptop running Vista Premium.  I replaced the stock "sights" folder in the game with the "sights" folder from my desktop.  The desktop "sights" folder has many custom sights.  
When I open the game on the laptop, it does not recognize the custom sights in the "sights" folder I replaced.
Anyone have a fix for this ?  I've done fresh installs twice, and replaced the original "sights" folder with the custom "sights" folder.  No problem on my desktop, Dell XPS running Windows XP Pro.
Thanks.