Just since a couple of days my Mac Pro desktop has been having display issues. Unexpectedly the screens go into sleep mode, it turns black and freezes, the computer doesnot respond to the keyboard or mouse. At first I thought this was related to Chrome, and switched to Firefox, but the computer is still having the same issue. I have to shut down and restart each time it gets stuck. I even went into preferences and changed the energy saver settings to "Never" allow display or harddrive to sleep. But this problem is stil happening. Does anyone have the same problems? Or a solution?