I know there are a billion threads on this already, but I thought I'd start a new one. 2008 Mac Pro w/ ATI 5770 viddy running 10.8.5. Freezes constantly forcing hard power downs. Suck. Pressing power button gives me a Shut Down/Restart/Log Off dialog, but... I am helpless to interact for the non-responsive keyboard and mouse. Seems to happen mostly when Chrome is open. Apple hates Google, Google hates Apple. I have hardware acceleration disabled. Thoughts besides "don't use Chrome?"