Emacs 23 - unable to use mouse scroll on windows vista

[fkunze]

On Microsoft Windows Vista, with emacs 23.1, mouse scroll does not
work as expected. If
you split windows and change to the new window, the mouse still
scrolls the
previous window. Here's how to reproduce the behavior:

1. Run emacs 23.1
2. Open a text file
3. Split the window with C-x 2
4. Change to other window and try to scroll with the mouse (you end up
scrolling the initial window)

I get this behavior with two different computers:
  1 -  a Lenovo t61 running the (formerly IBM) trackpoint mouse
software that permits scrolling when you put pressure on a small stick
located in the middle of the keyboard,
   2 - a Dell XPS with an older IBM trackpoint keyboard (also running
drivers similar to the computer above.

I've tried setting mouse-wheel-follow-mouse to both t and nil. I've
experimented with mouse-wheel-mode.  All to no avail.

Running C-h k and scrolling the mouse in the other buffer returns:

    <vertical-scroll-bar> <mouse-1> (translated from <mouse-1>) at
that
    spot runs the command scroll-bar-toolkit-scroll, which is an
    interactive compiled Lisp function in `scroll-bar.el'.

    It is bound to <vertical-scroll-bar> <mouse-1>.

    (scroll-bar-toolkit-scroll event)

    Not documented.

Some posts suggest that replacing the vendor-supplied mouse drivers
might solve this problem, but in my case I will lose the functionality
offered by IBM and Lenovo's trackpoint mouse.  Does anyone know how to
work around this problem?