Mighty Mouse Won't Pair With Mac

After reinstalling my mighty mouse software after accidentally uninstalling it, my mighty mouse will no longer pair with my mac mini.

What happens is that I follow the Bluetooth wizard for connecting a new device, select mouse as the device, then I get stuck on the screen that follows. The screen is the one where it says "Pairing with the mouse - This computer will use an empty passkey to pair with your device if possible". On that screen I get the spinning (device) icon and next to it "Connecting to <my name's> mouse". And it just stays on this screen until I close it.

I've tried installing it as "any device" but also run into the same problem. I've also tried setting up a new admin account to install it under but get the same problem.

Also, as soon as I switch the mouse on, the light starts flashing on the base of the mouse. I've also tried changing batteries to no avail.

Can someone help me?

Thanks

Paul