Bluetooth problem with M-RBB-DEL4 mouse, Optiplex 980 and Windows 7 64-bit

I recently upgraded from an older Optiplex model to a 980 and I'm unable to get my Bluetooth mouse to work on the new machine.  It's a model M-RBB-DEL4 and it was working perfectly on the old machine last week.

The 980 has Windows 7 Enterprise installed and everything is working fine except the mouse.  The Bluetooth radio is shown as working in the Device Manager and the mouse shows up as a Bluetooth Peripheral Device under Control Panel\Hardware and Sound\Devices and Printers.

I've tried removing the mouse from Control Panel\Hardware and Sound\Devices and Printers and adding it back.  The mouse seems to be detected correctly; Windows adds the device, etc., successfully, and reports all is well.  Yet the mouse still does not function.

Any ideas?