Microsoft Designer Mouse Stopped working with Macbook Air

I was using the Designer mouse with no trouble with my Air. One day my son needed to use it with his PC so I let him. Then when I got the mouse back it wouldn't work with my Air. I am running the right Bluetooth software. The mouse airs, says connected, doesn't work and then after a few seconds shows disconnected and never really connects. I have removed the device and added it several times and the same thing. I have also debugged bluetooth and reset the bluetooth device and still nothing. Any advice. I have tried everything I can find. What's annoying is that it was working fine and something has changed to keep it from working.