So I was testing ElementaryOS out using the 32bit Freya LiveCD, and went to grab some coffee and make a call. I returned to a black screen; moving the mouse seemed to "try" and bring the system out of sleep. However it appeared to get caught in some sort of loop where the screen kept trying to come to life, but wouldn't, I could see the mouse cursor appear and disappear over and over on a black background. This is 100% reproducible on a variety of machines, from desktops to laptops. Any ideas what might be going on here? I hope this won't happen with the installed version, but I haven't installed it yet... so...
I had this problem as well when I was testing it, I am a newbie so I searched a few guides and I found one that said to do a : rm -v .XAuthority this file is in /home/username(replace username with the user you want to delete) you can delete it for the default user and for your user as well. this fixed my blackscreen at logout problem right away. Also After that I ran to another problem where I had to manually edit configuration files to stop the elementary user to autolog with sudo rights. Tell me if you need more help. Ps. I am using a Iive usb instalation with 4gig persistent memory.
