Currently Being ModeratedFeb 28, 2012 8:08 AM (in response to virginiafrompunta gorda)
The mouse won't pair with a new machine while it's connected to another Mac. There are ways to pair with both machines and only connect to one but it would be easier to just disconnect and unpair it from your iMac, then it will be recognized and pair with the MacBook Pro.
To unpair on the iMac, Go to System Preferences > Bluetooth > click on the mouse on the left > click the "-" icon below the list.
Thank you. I have my MacBook at another location now and as soon as I turned it on, it connected to the mouse. I figured that was the problem as I had the two computer side by side originally. Again, thanks for the information.