The trackball uses standard windows built in drivers. I have an individual one for each computer (5) and one multicast to computers 2-5. The multicast one will convert clicks on either button 4-5 as clicks on physically non-existant button3. In my case it happens to be useful but it is odd. I used to use wireless trackball(s) before and that had all the buttons functioning normally (also windows drivers).

Ziran