1. Open a web page using Galeon. Be sure the page is long enough that the
right vertical scroll bar can appear;
2. Press down your mouce's button 1 on the scrollbar and hold it(do not let
the button up), and move your mouce pointer to one of Galeon's toolbars or
it's menubar when holding button 1 down, then let it(button 1) up.
3. After that, move your mouce pointer to the main browser area. OK, by now
you will see the scrollbar moves with you pointer moving, as if you draged
it as normal.

Well, this my first bug report here. And this is my first step seeking to
contribute something to my favourite desktop(Gnome of cause). So, please be
patient if I made something wrong here. :-)