Tonight I discovered that my headphone jack isn't working as expected: the machine always uses the internal speaker, no matter what I plug into the jack. System Preferences only ever shows "Internal Speakers" in the sound output device list. The line-in jack does work as expected. HOWEVER, in the course of testing I discovered a little twist: if I reboot with something plugged into the headphone jack, the computer recognizes it and uses it. System Preferences correctly lists "Headphone port" as the output device. As soon as I unplug the headphones or speakers from the jack, it goes back to the internal speaker as expected. But then it will no longer recognize anything new plugged into the jack. Is anyone else seeing this behavior? I don't know if this also happened on my 2007 mini because I had external speakers connected 100% of the time, including at startup (and I guess that could be a workaround for this one). But I can't imagine that's the standard, expected behavior? I currently have an appointment at the "Genius" Bar tomorrow morning. Assuming this is a defect, it'll be a hassle to be without the machine as I just got it all setup and everything moved over. Ugh. I already dismantled it to remove my 3rd-party SSD for warranty service, which was a pain. Should have tested this before installing the SSD last week!