I've got a 4,1 MP flashed to a 5,1. When holding the Option key on boot to bring up the start up manager is extremely slow, maybe 20 seconds or more. My previous 3,1 and first generation Mac Pro's did not have this problem, though they did have a problem using start up keys using an aluminum keyboard. I've tried various resets to no avail. I can't recall if it did this as a 4,1 as I upgraded right away. Any suggestions?