lose its connection to the mac after a certain amount of time? I ask because both my old MS BT mouse and my new Radtech BT 600 do, and I hate it. I only want the mouse to lose the connection when I turn it off, not after 2/3/5 minutes to save power. As I've explained in another thread, I'm losing patience with the BT 600, and if the mighty mouse works properly in this regard, I may break down and get one. TIA!