I installed 5160 on several machines with no problem, but on two I just got the spinning ball or nothing at all happened. On each I unplugged the existing mouse (one was a Logitech ball and the other was an Evoluent Verticle Mouse) and used a Kensington Si300 Laser Mouse, and ... 5160 installed perfectly on each machine! Not sure if it was those particular mice on each or just coincidence, but at least things are installed!
