When I hook up a mini toslink to my MBP it used to work just fine. Then one time when I hooked it up, it changes the sys preferances over to optical out just fine but I don't get any output. After a restart that fixed the problem last time. This time, doing the same thing, restart is a no go. My receiver doesn't even acknowledge a signal is being sent, and if you unplug it there is no red beam of light like there should be when it is getting a signal. If I unplug it the music plays through the built in speakers just fine. Any suggestions?