I am wondering if we can narrow down what is causing this.
Several times it has happened, I have been playing a video in Safari. This could just be a coincidence. The video has continued to play with the audio, but the rest of the system has frozen. Has anyone else been playing a video when this has happened?
Is this happening on older systems? My iMac is a 24" mid-2007.
What apps are people 1) using and 2) have running in the background when this happens for them?
I usually have running: Mail, Safari, iTunes, Pages and Evernote. I have been using Safari and (once) Pages when this happened.