I recently purchased an Apple wireless keyboard and mouse for my Powermac G5. Since then, I've been getting the following message on my screen whenever I wake my computer from sleep in the morning (I put it to sleep overnight): "You must shut down the computer. Press and hold the power button on the computer". The screen dims a bit, and I can't control the mouse or keyboard. This only happens when the computer has been asleep for at least 8 hours. My firmware and BT software is up to date. I don't know if the wireless keyboard and mouse have anything to do with this, but I didn't start getting the message to shut down the computer until a week after I started using them.