I'm experiencing a lot of kernel panics in Mountain Lion. Basically what is occurring is that I am working on my computer (often in Mail or Safari) and the system just freezes for about 5 seconds, then both screens go black and the computer restarts. Now, I'm on a 2009 Mac Pro with 20GB RAM and plenty of HD space. I have two monitors one is an LED and the other is an older (better) matte Cinema Display. I'm wondering if it's a graphic card issue, since on reboot I often see a weird band of colored pixels running across both monitors as the machine recovers and opens programs that were open during the crash. I have tried reinstalling the OS, zapping PRAM at the suggestions of others to no avail. Thoughts?