I have been having some issues with bluetooth on the new 24" iMacs. Basically the Mighty Mouse will stop functioning (No clicking, tracking or scrolling) even though it still shows it connected in the menu. Turning the mouse on and off does not work. Removing the batteries and re-inserting them does not work. I have to plug another mouse in, disconnect the mouse from the menu and then reconnect the mouse. Happens about every other day and it is ANNOYING!!!