If I leave the screensaver on random, the computer will be locked up by morning. Not sure which screensaver is causing the problem or if it is OpenGL related. Maybe someone else has noticed this?
When we get to the release candidate stage maybe the random feature can be turned off, so a new user does not experience the problem and imagine the worst.
This appears to have happened to me overnight. I left the computer on all night but in the morning, neither the keyboard nor mouse responded and I had to turn off the computer.
I turn off the monitor when I won't be using the computer for a while, but of course the screensaver will still run according to its settings.