I've recently had a problem where Safari will close by itself in the background. It doesn't throw up an error message, and I definitely don't quit it manually. I will close all open Safari windows, switch to another app, verify that Safari is still open, and keep working. Then I go back, and Safari has quit by itself in the background. I've got 16GB of RAM and this happens independently of memory load. It also occurs on AC and battery. Thanks for the help!