I've been using a mac for one year and I've never encountered that issue like that for a year. I just attempted to download new update of Thunderbolt Firmware update 1.2 which was downloaded successfully then, it required me to restart computer. Well, I did anyway. Before shutting down itself there was software installment screen before shut it down which is installed successfully. After Software loading, computer was restarted, as matter of fact Computer shut it down itself when main loading screen came out on screen. I've tried 3rd time at least to install that software onto computer which I've had enough to install it over and over again. Well, Have you guys encountered that inconvenient problem ? By the way Mac model is Macbook Pro 17 inch Late 2011 which is installed in Mac os X Mountain Lion.