Note: I've reported this bug before (with version 0.8* or earlier) but I
can't find it in the bug database. It's still in 0.11.

The problem:
Sometimes, the browser keep scrolling when I move the mouse even though I
have already released the mouse button.

How to reproduce:
* Go to a page that has a vertical scrollbar.
* Click on the scrollbar and hold the mouse button
* Drag the scrollbar to scroll up.
* Keep the mouse button pressed. Move the mouse further up beyond the
  scrollbar and beyond the up arrow button.
* Release the mousebutton (with the mouse still inside the galeon window)
* Move the mouse back down next to the scrollbar. The page will scroll down
as if you were still pressing the mouse button.

This problem also occurs when you are scrolling with the mouse button
pressed down and a popup window appears.

It's quite annoying :-(
Let me know if you have problems reproducing this.