>Paul,
>
>The "thing" is called the scrollbar thumb.
>
>It might be a video driver problem. I assume scrollbars in other apps behave differently? You might check the Appearance settings for the Desktop Properties.

Thanks, David, for that tidbit. All scroll bars in my other applications behave normally. Appearance settings are set to 'Windows Standard'.

Again, there's nothing fatal about this problem, but it's giving me a headache.

Thanks again...