Anyone have any luck finding a way to quiet the start up chime on a 4th generation white MacBook with OS X 10.7.2? (MacBook 4,1) StartupSound.prefPane doesn't work, and Psst only works if I remember to run it before shutting down. I know that the start up chimes are used to show that the computer has passed certain diagnostic tests at start up, so I am asking to quiet the volume, not mute it. I am not very good at predicting the future so I am not going to remember to turn down the volume the last time I shut down before taking my computer into a library or classroom, but I don't want to announce to the whole library or class that I have a MAC when I turn it on. Any suggestions?