I'm having the strangest thing happen on my Mac Mini (mid 2011). For what it's worth, I've upgraded to Yosemite. A while back, I noticed that the mini wasn't responding to IR commands. I went to check in the SECURITY & PRIVACY menu under ADVANCED, and sure enough, there was no option available to disable IR. Based on what I've read online, that means that somehow my Mini has lost ability to receive IR signals. I decided to try a clean install of Yosemite from a bootable USB I have, but I couldn't get the Mini to restart while holding down the option key. The best I could do was to get the Mini to restart while holding down Command + R. Via this method, Apple verified my machine, and I was able to download and reinstall Yosemite. Sure enough, once Yosemite reinstalled, my Mini was once again able to receive IR codes. I use my Mini as a HTPC, so I usually leave it running. However, when I restart, I lose IR functionality, and looking again in SECURITY & PRIVACY, I see that I've lost all mention of IR once again. So I reinstall Yosemite (via Command + R, not via the option key at startup), and IR reappears. I just restarted my computer for an update, and I've lost IR functionality again. As I've now gone through this sequence 3-4 times, I'm pretty tired of reinstalling Yosemite, so I thought I'd check and see if anyone might have a better solution? Yosemite honestly doesn't do anything for me on this machine, so I'd be just as happy to reinstall Mountain Lion (I also have a bootable USB), but as I can't restart the Mini when holding down the option key, I can't even do this. Might anyone have any ideas?