I wanted to do the 4,1 to 5,1 firmware update with the Mac Pro 2009-2010 Firmware Tool, but it seems that the Mac Pro does not want to update when I restart. The instructions says to hold the power button while starting up and let it go when the power LED blinks or when there is a long beep. I let go of the power button when it starts blinking but it just boots normally. I tried letting go after it stops blinking but before the long beep but that also just boots normally. Also there is a long beep but maybe 3 seconds after the blinking stops, I'm not sure if I should hold the power button until it beeps and then let go or let it go after both blinking and the beep stops.