I am running Linux Mint 12 with Cinnamon and sometimes when I leave my computer idle for a while, it will lock the screen. Usually, when I move the mouse a login prompt will pop up, but sometimes it doesn't. Then it's just a black screen with the time and my full name on a bar at the top of the screen. I can move the mouse, but nothing happens when I click on anything. When this happens I am forced to hard shutdown my computer, which is obviously not good. Does anyone know how to solve this?
Solving the issue would involve understanding why it is happening. You should start by looking through your logs to see if there are any obvious errors; begin with
To avoid having to do the hard shutdown, next time it happens, switch to a console with CtrlAltF1 (or any of the F_ keys between 1 and 6) and login and restart the display manager with:
You can then switch back to the console that