Originally Posted by Tallest Skil
Immediately after hitting Sleep, turn the Magic Mouse off. You have to have it turned off before the fans stop and the hard drive ticks to signify the beginning of sleep.
Works every time. Been doing it since launch.
And you have to do it this way instead of unticking " Allow Bluetooth devices to wake this computer" if you want to be able to use the mouse to wake it when you want it woken, obviously.
Otherwise just untick that box.
Your trick doesn't seem to work from the login screen.
One thing you absolutely DON'T want to do, evidently, is to turn off the mouse then use the power button on the machine to sleep. After doing this, I've found absolutely no way to connect the mouse again without restarting.