New solution found! Almost...
So I tried the tricks installing KMW 6.2.2 and then restarting, but no
matter what it did, it could not find my driver for my mouse, so I only
got the basic Vista mouse options screen. With this, only the scroll
wheel and left/right buttons work, not buttons 3,4, or 5.

The new solution, almost is to install Intelipoint. Pick almost any
mouse that has at least the same number of buttons as your Kensington
Mouse, if not more. This almost works because you get the basic
functions of buttons 3 and 4 (forward and back), but you cannot program
them. So, right now, my little front button thinks it is number 3, not
number 4 and vice versa. Even if I go into Intelipoint and change the
task for the button, it still does not change on the mouse. But at
least I have more functionality.

I am going to try an older Intelipoint and also something from Logitech
or a few other mouse makers.

For reference, I have the Kensington Ci20 Optical Mouse. I use this
mostly for the size of the mouse. It fits my hand well and it was only
$30.


--
stubek