Yesterday I have upgraded my ATI proprietary driver to 12.1. After some small issues it installed correctly, I have confirmation in Catalyst that the driver is at version 12.1.
Today I have noticed that after each log out, when I try to log back in, the screen freezes on my wallpaper. The mouse is working fine. CTRL-ALT-Backspace resets the Xserver, and prompts me back to the log in page. If I try a login, same thing happens. If I reboot from the login screen, I can log in into Unity 3D without any issue.
The issues happen only if I try to log-out and then back in. If I log in on Ubuntu 2D, it works fine.
So, any Ideas?
Edit: I think that's what's happening when I try to re-login. Taken from /var/log/syslog:
gnome-session[3017]: Gdk-WARNING: gnome-session: Fatal IO error 11 (Resource temporarily unavailable) on X server :0.#012
kernel: [ 1124.496537] [fglrx] IRQ 49 Disabled
Edit 2:
I have reverted to the drivers 11.12 and 11.10 (currently using it) and the behavior is the same. The problem is that I don't remember if I had this problem before or not. I would guess not, so, something is wrong here. It's not a show stopper for me, because I don't need to log-out / log-in, but still it's an error.