Yes, but do you also have a trackball with not only 4 buttons but a
scroll wheel, as described in my earlier message?
Actually, in order to use all those features you have to install some
supplemental drivers which come with the Microsoft trackball.
I used the additional software for a while, but finally decided to
remove it and use only the primary left and right buttons, the
trackball (best feature of all), and the thumb scroll wheel which is
nice for reading long mail and scanning down website pages. It's set
to scroll 3 lines per click.